{
 "dataset": {
  "name_zh": "NTJ 日語學習作答彙總資料集 2026 年 8 月",
  "name_en": "NTJ Japanese Learning Answer Dataset — August 2026",
  "version": "1.1.0",
  "methodology_version": "1.1",
  "snapshot_date": "2026-08-14",
  "generated_at_utc": "2026-08-14T14:46:47Z",
  "cutoff_utc": "2026-08-14T00:00:00Z",
  "temporal_coverage": "2026-08-02/2026-08-13",
  "note_first_day_partial": true,
  "publisher": "Nihongo to Japan",
  "url": "https://www.nihongotojapan.com/research/japanese-learning-data-2026",
  "license_status": "CC-BY-4.0"
 },
 "license": {
  "status": "CC-BY-4.0",
  "spdx": "CC-BY-4.0",
  "url": "https://creativecommons.org/licenses/by/4.0/",
  "scope_zh": "CC BY 4.0 **只涵蓋資料本身**：本頁的彙總統計數字，以及 japanese-learning-2026.json 與 japanese-learning-2026.csv 兩個下載檔。本站製作的圖表（SVG／PNG）與報告全文**不在授權範圍內**，仍保留權利。",
  "scope_en": "CC BY 4.0 **covers the data only**: the aggregate figures on this page and the two downloadable files (japanese-learning-2026.json and japanese-learning-2026.csv). The charts produced by Nihongo to Japan (SVG/PNG) and the text of the report are **not covered** and remain rights-reserved.",
  "note_zh": "資料採 **CC BY 4.0**：可自由重製、散布、改作與再發布，**包含商業用途**，唯一條件是適當標示出處並註明是否修改過。⚠️ CC BY 是**不可撤回**的授權——任何依此條款取得資料的人，其權利不因本站日後變更條款而失效。",
  "note_en": "The data is released under **CC BY 4.0**: you may copy, redistribute, adapt and build upon it, **including commercially**, provided you give appropriate credit and indicate if changes were made. ⚠️ CC BY is **irrevocable** — anyone who receives the data under these terms keeps those rights even if the publisher changes the terms later.",
  "permitted_zh": [
   "在論文、研究報告、教學材料、新聞報導中引用本資料集的統計數字，包含商業出版品。",
   "重新分析可下載的彙總數字，並自行製作新的圖表（新圖表是你的）。",
   "改作、混合、轉換，並以任何形式再發布，包含整批再散布資料檔或放進自己的資料產品。",
   "在課堂與教育場合使用，不需事先取得同意。"
  ],
  "permitted_en": [
   "Cite the statistics in papers, research reports, teaching materials and journalism, including commercial publications.",
   "Re-analyse the downloadable aggregate figures and produce your own charts (those charts are yours).",
   "Adapt, remix, transform and redistribute in any form, including redistributing the data files wholesale or including them in your own data product.",
   "Use in classrooms and educational settings without asking first."
  ],
  "attribution_zh": "Nihongo to Japan,《日語學習作答彙總資料集・2026 年 8 月》v1.1.0, CC BY 4.0, https://www.nihongotojapan.com/research/japanese-learning-data-2026",
  "attribution_en": "Nihongo to Japan, Japanese Learning Answer Dataset — August 2026, v1.1.0, CC BY 4.0, https://www.nihongotojapan.com/research/japanese-learning-data-2026",
  "requested_zh": [
   "引用時一併帶上樣本限制（自選觀察性樣本、只有 12 天、非代表性）。這是**請求不是授權條件**——但拿掉限制轉述數字，等於發布一則誤導性的統計。",
   "連結回本頁，讓讀者看得到方法與版本。",
   "用「learner identifiers」而不是「人數」；identifier 是自然人數的上界。",
   "一併寫出版本號（例：v1.1.0，snapshot 2026-08-14），日後數字更新時你引用的那一版仍可被指認。"
  ],
  "requested_en": [
   "Carry the sampling limitations alongside the figures (self-selected observational sample, 12 days only, not representative). This is a **request, not a licence condition** — but quoting the numbers without them publishes a misleading statistic.",
   "Link back to this page so readers can see the methodology and the version.",
   "Say \"learner identifiers\" rather than \"people\"; the identifier count is an upper bound on the number of people.",
   "State the version (e.g. v1.1.0, snapshot 2026-08-14) so the figures you cited stay identifiable after later updates."
  ],
  "not_covered_zh": [
   "本站製作的圖表（public/images/research/*.svg 與 *.png）：**不在 CC BY 範圍**，轉載請先來信取得同意。你可以用資料自己畫新圖，那不需要同意。",
   "報告全文與網頁文字：**不在 CC BY 範圍**，保留權利。",
   "站台名稱、標誌與品牌識別：不因本授權而可使用。"
  ],
  "not_covered_en": [
   "The charts produced by Nihongo to Japan (public/images/research/*.svg and *.png): **not covered by CC BY** — please contact us before reproducing them. Making your own charts from the data needs no permission.",
   "The text of the report and of this website: **not covered by CC BY**; rights reserved.",
   "The site name, logo and brand marks: this licence grants no rights to use them."
  ],
  "contact": "https://www.nihongotojapan.com/research/japanese-learning-data-2026#contact"
 },
 "definitions": {
  "answer_event": {
   "zh": "一名學習者對一道題目的一次作答。以前端產生的事件 UUID 為主鍵，重送不重複計。",
   "en": "One learner answering one question once. Keyed by a client-generated event UUID; re-sends are de-duplicated."
  },
  "learner_identifier": {
   "zh": "一個匿名的 learner identifier（瀏覽器端隨機產生的 UUID）。不含姓名、email、IP。**跨裝置無法合併**，因此同一個人使用多個裝置會產生多個 identifier；此數字不是經驗證的不重複自然人數，只是人數的上界。",
   "en": "One anonymous learner identifier (a UUID generated at random in the browser). No name, email or IP. **Identifiers cannot be merged across devices**, so one person using several devices produces several identifiers. This count is not a verified number of distinct people — it is an upper bound."
  },
  "accuracy": {
   "zh": "raw accuracy = 答對數 ÷ 有效作答數。不是能力值估計，未做難度等化。",
   "en": "raw accuracy = correct answers ÷ valid answer events. Not an ability estimate; no difficulty equating."
  },
  "analysis_set_quiz_first_attempt": {
   "zh": "測驗情境首答（主要分析集合）：來源為 challenge／placement_test／special_training 的作答，且為該 learner identifier 對該題的首次作答、非 24 小時內重複、題目後設資料完整。⚠️ 這個集合**不宣稱**「未使用提示」或「未先看解析」——那些欄位不可觀測（見 telemetry_status）。",
   "en": "Quiz-context first attempts (primary analysis set): answers from challenge / placement_test / special_training where this is the learner identifier's first attempt at that question, not a repeat within 24 hours, and the question metadata is complete. ⚠️ This set makes **no claim** about hints or explanations — those fields are unobservable (see telemetry_status)."
  },
  "analysis_set_lesson_first_attempt": {
   "zh": "教材情境首答（對照集合）：來源為 self_study／review 的首次作答，也就是「剛讀完教材後在課內作答」。",
   "en": "Lesson-context first attempts (comparison set): first attempts from self_study / review — answers given while working through the lesson material."
  },
  "analysis_set_first_attempt": {
   "zh": "全情境首答：每個 learner identifier 對每道題目的第一次作答，不分來源。",
   "en": "First attempts (all contexts): each learner identifier's first answer to each question, regardless of source."
  },
  "analysis_set_all_events": {
   "zh": "全部作答：所有有效作答事件，含重複作答。",
   "en": "All answer events: every valid answer event, including repeats."
  },
  "skill_axis": {
   "zh": "題目在出題時被標記的能力軸向（快照值，事後改題庫不會回頭改事件）。",
   "en": "The skill axis the question carried at answer time (a snapshot; later question-bank edits do not rewrite past events)."
  },
  "jlpt_level": {
   "zh": "題目在出題時被標記的 JLPT 級別（快照值）。**不同級別的題目集合不同，不可直接比較難度。**",
   "en": "The JLPT level the question carried at answer time (a snapshot). **Different levels draw on different question sets; raw accuracy is not a difficulty comparison.**"
  },
  "knowledge_point": {
   "zh": "更細的知識點標籤。`kp_<軸>_bucket_<級別>` 是該軸該級別的統包桶；`kp_particle_<助詞>` 是單一助詞。",
   "en": "A finer-grained knowledge tag. `kp_<axis>_bucket_<level>` is a catch-all bucket for that axis and level; `kp_particle_<particle>` is a single particle."
  },
  "flag": {
   "zh": "OK＝n≥100 且 learners≥5，可直接引用；LOW_SAMPLE＝n≥30 且 learners≥5，引用時務必附 n；SUPPRESSED＝樣本過小，只公開事件數、不公開正確率。",
   "en": "OK = n≥100 and learners≥5, safe to cite; LOW_SAMPLE = n≥30 and learners≥5, always cite with n; SUPPRESSED = sample too small, event count published but accuracy withheld."
  },
  "telemetry_unobservable": {
   "zh": "used_hint／viewed_explanation／used_answer_key 三個欄位在整個資料庫裡都是 false，但那是因為沒有任何前端呼叫點寫入它們（產品目前也沒有作答前提示或看答案的功能）。全 false 是儀器的性質，不是學習者行為的證據，因此不作為任何分析條件。",
   "en": "The fields used_hint / viewed_explanation / used_answer_key are false throughout the database, but only because no producer ever writes them (the product currently has no pre-answer hint or answer-reveal feature). The constant false is a property of the instrumentation, not evidence about learner behaviour, and is not used as an analysis condition."
  },
  "ci95": {
   "zh": "Wilson 95% 信賴區間（比常態近似在小樣本更穩健）。它只反映抽樣誤差，不修正選樣偏差。",
   "en": "Wilson 95% confidence interval (more robust than the normal approximation at small n). It reflects sampling error only and does not correct for selection bias."
  }
 },
 "methodology": {
  "population": {
   "zh": "使用 Nihongo to Japan 的學習者所產生的作答紀錄。",
   "en": "Answer records produced by learners using Nihongo to Japan."
  },
  "sampling": {
   "zh": "自選、觀察性樣本（self-selected, observational）。非隨機抽樣，非人口代表性樣本。",
   "en": "Self-selected, observational sample. Not random sampling; not population-representative."
  },
  "unit_of_analysis": {
   "zh": "answer event（一次作答）",
   "en": "answer event"
  },
  "user_count": {
   "zh": "learner identifiers＝不重複的匿名識別碼數（跨裝置無法合併，是自然人數的上界）",
   "en": "learner identifiers = count of distinct anonymous identifiers (cannot be merged across devices; an upper bound on the number of people)"
  },
  "metric": {
   "zh": "raw accuracy = 答對數 ÷ 有效作答數",
   "en": "raw accuracy = correct ÷ valid answer events"
  },
  "exclusions": {
   "zh": [
    "已知退化題目（教材填空非文法題誤入句型軸、舊版今日一題把不同題合併成同一 id）共 520 個 question_id，透過 denylist 從所有聚合排除。",
    "快取截止時間之後的事件（凍結 snapshot）。"
   ],
   "en": [
    "Known degraded questions (non-grammar cloze items mis-tagged into the pattern axis; an older daily-question build that collapsed different questions onto one id) — 520 question_ids excluded from every aggregate via a denylist.",
    "Events after the snapshot cutoff (the snapshot is frozen)."
   ]
  },
  "limitations": {
   "zh": [
    "**選樣偏差**：樣本是會主動來刷題的人，不代表一般學習者，更不代表全體台灣人。",
    "**重複測量**：同一個 learner identifier 可貢獻上千筆作答。單一 identifier 最多佔全部事件的 3.7%，前 10 名佔 19.4%。在完全相同的 372 個 identifiers、相同分析集合、相同 eligible events 上重算：事件加權 82.5%、每人一票 75.5%，weighting effect = 7.04 個百分點。",
    "**分析集合差異主要來自情境組成，不是計算規則**：句型軸的觀察正確率在不同集合下從 53.7% 到 74.1%。分解顯示重複作答只佔 0.9 個百分點，其餘幾乎全部來自「教材情境」與「測驗情境」的差異——兩者納入的作答、learner identifiers 與**題目集合**都不同。同題比較無法進行（見 matched_same_question_pattern），因此不能把差異全部歸給情境。",
    "**題目難度不一**：各級別、各軸向的題目集合不同，raw accuracy 不是難度的標準化度量。",
    "**未做 IRT 等化**：沒有做項目反應理論的難度等化，因此不能跨級別比較「哪一級比較難」。",
    "**樣本量不均**：N5 的作答數遠多於 N1。",
    "**時間窗很短**：資料只涵蓋 12 天（聚合管線 2026-08-02 才上線），沒有長期趨勢可言。",
    "**非母體代表**：不代表台灣、也不代表任何國家的日語學習者全體。"
   ],
   "en": [
    "**Selection bias**: the sample consists of people who chose to practise on this site. It does not represent Japanese learners in general, still less the population of Taiwan.",
    "**Repeated measures**: one learner identifier can contribute thousands of answers. The single most active identifier accounts for 3.7% of all events and the top 10 for 19.4%. Recomputed over exactly the same 372 identifiers, the same analysis set and the same eligible events: event-weighted 82.5%, one-vote-per-identifier 75.5% — a weighting effect of 7.04 percentage points.",
    "**Analysis-set differences come mainly from context composition, not from the counting rule**: observed accuracy on the grammar-pattern axis ranges from 53.7% to 74.1% across analysis sets. Decomposition attributes about 0.9 points to repeat attempts; almost all of the remainder comes from the difference between lesson-context and quiz-context answers, which differ in the events included, the learner identifiers involved, and **the questions asked**. A same-question comparison is not possible (see matched_same_question_pattern), so the difference cannot be attributed to context alone.",
    "**Unequal question difficulty**: each level and axis draws on a different question set; raw accuracy is not a normalised measure of difficulty.",
    "**No IRT equating**: no item-response-theory difficulty equating was performed, so raw accuracy cannot be used to say which JLPT level is objectively harder.",
    "**Unequal sample sizes**: there are far more N5 answers than N1 answers.",
    "**Short time window**: the data covers 12 days only (the aggregation pipeline went live 2026-08-02). No longitudinal trend can be read from it.",
    "**Not population-representative**: it does not represent all Japanese learners in Taiwan or anywhere else."
   ]
  },
  "privacy": {
   "zh": [
    "事件只帶一個前端隨機產生的匿名裝置 UUID。**沒有姓名、email、IP、裝置指紋或任何自由輸入文字。**",
    "接收端（Cloudflare Pages Function）只寫入白名單欄位，明確不寫 IP。",
    "公開資料集只有彙總統計，沒有任何一筆原始作答事件。",
    "最小格數門檻：n<30 或 learner identifiers<5 的細格不公開正確率。",
    "學習者可在隱私政策頁一鍵退出彙總收集。"
   ],
   "en": [
    "Each event carries only an anonymous device UUID generated in the browser. **No name, email, IP, device fingerprint or free-text input.**",
    "The receiving Cloudflare Pages Function writes whitelisted columns only and explicitly never writes IP.",
    "The public dataset contains aggregate statistics only — not a single raw answer event.",
    "Minimum cell size: cells with n<30 or learner identifiers<5 do not publish an accuracy figure.",
    "Learners can opt out of aggregate collection with one click on the privacy policy page."
   ]
  }
 },
 "totals": {
  "valid_answer_events": 56613,
  "learner_identifiers": 1053,
  "distinct_questions": 11987,
  "distinct_knowledge_points": 39,
  "first_attempt_events": 52934,
  "primary_set_events": 37245,
  "primary_set_learner_identifiers": 688,
  "lesson_set_events": 15741,
  "days_covered": 12
 },
 "thresholds": {
  "min_n_to_report": 30,
  "min_learners_to_report": 5,
  "min_n_for_headline": 100,
  "note": "n<30 或 learner identifiers<5 → SUPPRESSED（只報事件數，不報正確率）"
 },
 "composition": {
  "by_evidence_class": {
   "B": 17048,
   "A": 37245,
   "C": 2320
  },
  "by_source": {
   "challenge": 23369,
   "self_study": 16782,
   "placement_test": 11797,
   "special_training": 4157,
   "review": 508
  },
  "by_attempt_number": {
   "1": 52905,
   "2": 3119,
   "3": 453,
   "4": 96,
   "5": 40
  },
  "events_per_day": {
   "2026-08-02": 4057,
   "2026-08-03": 4002,
   "2026-08-04": 3294,
   "2026-08-05": 4638,
   "2026-08-06": 2930,
   "2026-08-07": 5572,
   "2026-08-08": 4102,
   "2026-08-09": 3309,
   "2026-08-10": 5905,
   "2026-08-11": 5515,
   "2026-08-12": 5583,
   "2026-08-13": 7706
  }
 },
 "telemetry_status": {
  "used_hint": "UNOBSERVABLE",
  "viewed_explanation": "UNOBSERVABLE",
  "used_answer_key": "UNOBSERVABLE",
  "note_zh": "這三個欄位在資料庫裡全部為 false，但那是因為**沒有任何前端呼叫點寫入它們**——全站 12 個作答捕捉點都沒有傳這些參數，而產品目前也沒有「作答前提示」或「作答前看答案」的功能。因此不能把全 false 解讀成「沒有發生」，也不能拿它們當分析條件。",
  "note_en": "All three fields are false throughout the database, but only because **no producer ever writes them** — none of the 12 answer-capture call sites passes these parameters, and the product currently has no pre-answer hint or answer-reveal feature. The constant false is a property of the instrumentation, not evidence about learner behaviour, and these fields are therefore not used as analysis conditions.",
  "response_time_ms": "MOSTLY_NULL"
 },
 "primary_set_verification": {
  "strict_set_events": 37245,
  "also_server_verified_first_attempt": 37094,
  "pct": 99.59,
  "mismatch": 151,
  "mismatch_note_zh": "差異推測為跨裝置：同一人在兩台裝置各答一次，每台都判定為首答",
  "mismatch_note_en": "The mismatch is most likely cross-device: the same person answering on two devices, each of which records a first attempt.",
  "attempt_number_all_1": true,
  "sources_present": [
   "challenge",
   "placement_test",
   "special_training"
  ]
 },
 "analysis_set_decomposition": {
  "overall": {
   "all_events": {
    "n": 56613,
    "accuracy": 0.8234,
    "learners": 1053
   },
   "first_attempt": {
    "n": 52934,
    "accuracy": 0.8186,
    "learners": 1053
   },
   "quiz_first_attempt": {
    "n": 37245,
    "accuracy": 0.8119,
    "learners": 688
   },
   "lesson_first_attempt": {
    "n": 15741,
    "accuracy": 0.8337,
    "learners": 622
   },
   "all_to_first_pp": -0.48,
   "first_to_quiz_pp": -0.67,
   "quiz_vs_lesson_pp": -2.18
  },
  "vocab": {
   "all_events": {
    "n": 24282,
    "accuracy": 0.924,
    "learners": 627
   },
   "first_attempt": {
    "n": 22891,
    "accuracy": 0.9214,
    "learners": 627
   },
   "quiz_first_attempt": {
    "n": 22869,
    "accuracy": 0.9213,
    "learners": 627
   },
   "lesson_first_attempt": {
    "n": 0,
    "accuracy": null,
    "learners": 0
   },
   "all_to_first_pp": -0.26,
   "first_to_quiz_pp": -0.01,
   "quiz_vs_lesson_pp": null
  },
  "pattern": {
   "all_events": {
    "n": 24293,
    "accuracy": 0.741,
    "learners": 816
   },
   "first_attempt": {
    "n": 22638,
    "accuracy": 0.7323,
    "learners": 816
   },
   "quiz_first_attempt": {
    "n": 8678,
    "accuracy": 0.5369,
    "learners": 532
   },
   "lesson_first_attempt": {
    "n": 13937,
    "accuracy": 0.8538,
    "learners": 424
   },
   "all_to_first_pp": -0.87,
   "first_to_quiz_pp": -19.54,
   "quiz_vs_lesson_pp": -31.69
  },
  "wordform": {
   "all_events": {
    "n": 3511,
    "accuracy": 0.7764,
    "learners": 450
   },
   "first_attempt": {
    "n": 3383,
    "accuracy": 0.7759,
    "learners": 450
   },
   "quiz_first_attempt": {
    "n": 2322,
    "accuracy": 0.8325,
    "learners": 386
   },
   "lesson_first_attempt": {
    "n": 1057,
    "accuracy": 0.6509,
    "learners": 90
   },
   "all_to_first_pp": -0.05,
   "first_to_quiz_pp": 5.66,
   "quiz_vs_lesson_pp": 18.16
  },
  "particle": {
   "all_events": {
    "n": 3096,
    "accuracy": 0.7148,
    "learners": 379
   },
   "first_attempt": {
    "n": 2627,
    "accuracy": 0.697,
    "learners": 379
   },
   "quiz_first_attempt": {
    "n": 1986,
    "accuracy": 0.6913,
    "learners": 137
   },
   "lesson_first_attempt": {
    "n": 747,
    "accuracy": 0.7189,
    "learners": 284
   },
   "all_to_first_pp": -1.78,
   "first_to_quiz_pp": -0.57,
   "quiz_vs_lesson_pp": -2.76
  },
  "idiom": {
   "all_events": {
    "n": 1380,
    "accuracy": 0.8652,
    "learners": 261
   },
   "first_attempt": {
    "n": 1344,
    "accuracy": 0.8646,
    "learners": 261
   },
   "quiz_first_attempt": {
    "n": 1341,
    "accuracy": 0.8643,
    "learners": 261
   },
   "lesson_first_attempt": {
    "n": 0,
    "accuracy": null,
    "learners": 0
   },
   "all_to_first_pp": -0.06,
   "first_to_quiz_pp": -0.03,
   "quiz_vs_lesson_pp": null
  },
  "reading": {
   "all_events": {
    "n": 24,
    "accuracy": 0.9583,
    "learners": 4
   },
   "first_attempt": {
    "n": 24,
    "accuracy": 0.9583,
    "learners": 4
   },
   "quiz_first_attempt": {
    "n": 22,
    "accuracy": 0.9545,
    "learners": 4
   },
   "lesson_first_attempt": {
    "n": 0,
    "accuracy": null,
    "learners": 0
   },
   "all_to_first_pp": 0.0,
   "first_to_quiz_pp": -0.38,
   "quiz_vs_lesson_pp": null
  },
  "allround": {
   "all_events": {
    "n": 27,
    "accuracy": 0.8889,
    "learners": 8
   },
   "first_attempt": {
    "n": 27,
    "accuracy": 0.8889,
    "learners": 8
   },
   "quiz_first_attempt": {
    "n": 27,
    "accuracy": 0.8889,
    "learners": 8
   },
   "lesson_first_attempt": {
    "n": 0,
    "accuracy": null,
    "learners": 0
   },
   "all_to_first_pp": 0.0,
   "first_to_quiz_pp": 0.0,
   "quiz_vs_lesson_pp": null
  }
 },
 "matched_same_learner_pattern": {
  "possible": true,
  "n_learner_identifiers": 75,
  "min_events_each_side": 5,
  "lesson_context": {
   "n": 5858,
   "accuracy": 0.8657
  },
  "quiz_context": {
   "n": 2055,
   "accuracy": 0.5552
  },
  "paired_mean_diff_pp": 27.47,
  "paired_median_diff_pp": 26.92,
  "paired_95ci_pp": [
   22.56,
   32.39
  ]
 },
 "matched_same_question_pattern": {
  "possible": false,
  "distinct_pattern_questions": 5772,
  "questions_seen_in_both_contexts": 6,
  "questions_with_ge3_each_side": 1,
  "reason_zh": "教材情境與測驗情境幾乎使用互不重疊的題目集合（5772 道句型題中只有 6 道兩邊都出現過，其中只有 1 道兩邊各達 3 筆）。因此**無法做同題比較**，也就無法把「情境效果」與「題目難度差異」分開。",
  "reason_en": "The two contexts draw on almost disjoint question sets: of 5772 distinct grammar-pattern questions, only 6 appear in both contexts and only 1 have at least 3 answers on each side. A same-question comparison is therefore **not possible**, and the context effect cannot be separated from differences in question difficulty."
 },
 "weighting_effect": {
  "cohort_definition_zh": "主要分析集合中作答數 ≥20 的 learner identifiers",
  "cohort_definition_en": "Learner identifiers with at least 20 answers in the primary analysis set",
  "n_learner_identifiers": 372,
  "n_eligible_events": 34392,
  "event_weighted": 0.8253,
  "learner_weighted": 0.7549,
  "learner_weighted_median": 0.7619,
  "WEIGHTING_EFFECT_PP": 7.04,
  "note_zh": "兩個數字用完全相同的 learner identifiers、相同分析集合、相同 eligible events 計算。",
  "note_en": "Both figures are computed over exactly the same learner identifiers, the same analysis set and the same eligible events.",
  "top1_share_of_all_events": 0.0373,
  "top10_share_of_all_events": 0.1944
 },
 "dimensions": {
  "analysis_set": [
   "quiz_first_attempt",
   "lesson_first_attempt",
   "first_attempt",
   "all_events"
  ],
  "primary_analysis_set": "quiz_first_attempt",
  "skill_axis": [
   "allround",
   "idiom",
   "particle",
   "pattern",
   "reading",
   "vocab",
   "wordform"
  ],
  "jlpt_level": [
   "N5",
   "N4",
   "N3",
   "N2",
   "N1"
  ],
  "knowledge_point": [
   "kp_conj_masu",
   "kp_conj_nai",
   "kp_conj_potential",
   "kp_conj_ta",
   "kp_conj_te",
   "kp_idiom_bucket_N1",
   "kp_idiom_bucket_N2",
   "kp_idiom_bucket_N3",
   "kp_idiom_bucket_N4",
   "kp_idiom_bucket_N5",
   "kp_particle_other",
   "kp_particle_か",
   "kp_particle_から",
   "kp_particle_が",
   "kp_particle_で",
   "kp_particle_と",
   "kp_particle_に",
   "kp_particle_の",
   "kp_particle_は",
   "kp_particle_へ",
   "kp_particle_まで",
   "kp_particle_も",
   "kp_particle_より",
   "kp_particle_を",
   "kp_pattern_bucket_N1",
   "kp_pattern_bucket_N2",
   "kp_pattern_bucket_N3",
   "kp_pattern_bucket_N4",
   "kp_pattern_bucket_N5",
   "kp_vocab_bucket_N1",
   "kp_vocab_bucket_N2",
   "kp_vocab_bucket_N3",
   "kp_vocab_bucket_N4",
   "kp_vocab_bucket_N5",
   "kp_wordform_bucket_N1",
   "kp_wordform_bucket_N2",
   "kp_wordform_bucket_N3",
   "kp_wordform_bucket_N4"
  ]
 },
 "variable_measured": [
  {
   "name": "n",
   "description_en": "Number of valid answer events in the cell"
  },
  {
   "name": "learners",
   "description_en": "Number of distinct anonymous learner identifiers contributing to the cell (not verified distinct people)"
  },
  {
   "name": "accuracy",
   "description_en": "Raw accuracy: correct answers divided by n"
  },
  {
   "name": "ci95_low / ci95_high",
   "description_en": "Wilson 95% confidence interval for accuracy"
  },
  {
   "name": "flag",
   "description_en": "OK / LOW_SAMPLE / SUPPRESSED — see definitions.flag"
  }
 ],
 "data": [
  {
   "dimension": "axis",
   "key": "allround",
   "label_zh": "綜合",
   "label_en": "Mixed / all-round",
   "category": "allround",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 27,
   "learners": 8,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis",
   "key": "idiom",
   "label_zh": "慣用表現",
   "label_en": "Idiomatic expressions",
   "category": "idiom",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 1341,
   "learners": 261,
   "accuracy": 0.8643,
   "ci95_low": 0.8449,
   "ci95_high": 0.8816,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "particle",
   "label_zh": "助詞",
   "label_en": "Particles",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 1986,
   "learners": 137,
   "accuracy": 0.6913,
   "ci95_low": 0.6707,
   "ci95_high": 0.7113,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "pattern",
   "label_zh": "句型／文法",
   "label_en": "Grammar patterns",
   "category": "pattern",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 8678,
   "learners": 532,
   "accuracy": 0.5369,
   "ci95_low": 0.5264,
   "ci95_high": 0.5473,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "reading",
   "label_zh": "讀解",
   "label_en": "Reading comprehension",
   "category": "reading",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 22,
   "learners": 4,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis",
   "key": "vocab",
   "label_zh": "詞彙",
   "label_en": "Vocabulary",
   "category": "vocab",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 22869,
   "learners": 627,
   "accuracy": 0.9213,
   "ci95_low": 0.9177,
   "ci95_high": 0.9247,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "wordform",
   "label_zh": "活用變化",
   "label_en": "Word forms / conjugation",
   "category": "wordform",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 2322,
   "learners": 386,
   "accuracy": 0.8325,
   "ci95_low": 0.8167,
   "ci95_high": 0.8471,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N1",
   "label_zh": "N1",
   "label_en": "N1",
   "category": null,
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 3040,
   "learners": 139,
   "accuracy": 0.7599,
   "ci95_low": 0.7444,
   "ci95_high": 0.7747,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N2",
   "label_zh": "N2",
   "label_en": "N2",
   "category": null,
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 2726,
   "learners": 212,
   "accuracy": 0.6937,
   "ci95_low": 0.6761,
   "ci95_high": 0.7107,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N3",
   "label_zh": "N3",
   "label_en": "N3",
   "category": null,
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 5985,
   "learners": 432,
   "accuracy": 0.6782,
   "ci95_low": 0.6662,
   "ci95_high": 0.6899,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N4",
   "label_zh": "N4",
   "label_en": "N4",
   "category": null,
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 6099,
   "learners": 313,
   "accuracy": 0.7344,
   "ci95_low": 0.7232,
   "ci95_high": 0.7453,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N5",
   "label_zh": "N5",
   "label_en": "N5",
   "category": null,
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 19395,
   "learners": 380,
   "accuracy": 0.9022,
   "ci95_low": 0.898,
   "ci95_high": 0.9063,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_masu",
   "label_zh": "動詞活用「masu」",
   "label_en": "Verb conjugation – masu",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 54,
   "learners": 18,
   "accuracy": 0.9815,
   "ci95_low": 0.9023,
   "ci95_high": 0.9967,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_nai",
   "label_zh": "動詞活用「nai」",
   "label_en": "Verb conjugation – nai",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 87,
   "learners": 19,
   "accuracy": 0.9655,
   "ci95_low": 0.9035,
   "ci95_high": 0.9882,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_potential",
   "label_zh": "動詞活用「potential」",
   "label_en": "Verb conjugation – potential",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 56,
   "learners": 19,
   "accuracy": 0.8929,
   "ci95_low": 0.7853,
   "ci95_high": 0.95,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_ta",
   "label_zh": "動詞活用「ta」",
   "label_en": "Verb conjugation – ta",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 89,
   "learners": 19,
   "accuracy": 0.9663,
   "ci95_low": 0.9055,
   "ci95_high": 0.9885,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_te",
   "label_zh": "動詞活用「te」",
   "label_en": "Verb conjugation – te",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 88,
   "learners": 19,
   "accuracy": 0.9659,
   "ci95_low": 0.9045,
   "ci95_high": 0.9883,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N1",
   "label_zh": "慣用表現（N1）",
   "label_en": "Idioms (N1)",
   "category": "idiom",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 742,
   "learners": 111,
   "accuracy": 0.8881,
   "ci95_low": 0.8634,
   "ci95_high": 0.9089,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N2",
   "label_zh": "慣用表現（N2）",
   "label_en": "Idioms (N2)",
   "category": "idiom",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 167,
   "learners": 62,
   "accuracy": 0.7665,
   "ci95_low": 0.6968,
   "ci95_high": 0.8242,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N3",
   "label_zh": "慣用表現（N3）",
   "label_en": "Idioms (N3)",
   "category": "idiom",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 290,
   "learners": 142,
   "accuracy": 0.8586,
   "ci95_low": 0.8138,
   "ci95_high": 0.894,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N4",
   "label_zh": "慣用表現（N4）",
   "label_en": "Idioms (N4)",
   "category": "idiom",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 140,
   "learners": 91,
   "accuracy": 0.8643,
   "ci95_low": 0.7977,
   "ci95_high": 0.9114,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N5",
   "label_zh": "慣用表現（N5）",
   "label_en": "Idioms (N5)",
   "category": "idiom",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 2,
   "learners": 2,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_other",
   "label_zh": "助詞「other」",
   "label_en": "Particles – other",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 34,
   "learners": 26,
   "accuracy": 0.7059,
   "ci95_low": 0.5383,
   "ci95_high": 0.8317,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_か",
   "label_zh": "助詞「か」",
   "label_en": "Particles – か",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 18,
   "learners": 14,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_から",
   "label_zh": "助詞「から」",
   "label_en": "Particles – から",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 52,
   "learners": 33,
   "accuracy": 0.6346,
   "ci95_low": 0.4987,
   "ci95_high": 0.752,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_が",
   "label_zh": "助詞「が」",
   "label_en": "Particles – が",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 358,
   "learners": 81,
   "accuracy": 0.6089,
   "ci95_low": 0.5575,
   "ci95_high": 0.6581,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_で",
   "label_zh": "助詞「で」",
   "label_en": "Particles – で",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 330,
   "learners": 85,
   "accuracy": 0.6333,
   "ci95_low": 0.5801,
   "ci95_high": 0.6835,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_と",
   "label_zh": "助詞「と」",
   "label_en": "Particles – と",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 99,
   "learners": 46,
   "accuracy": 0.8384,
   "ci95_low": 0.7535,
   "ci95_high": 0.898,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_に",
   "label_zh": "助詞「に」",
   "label_en": "Particles – に",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 370,
   "learners": 75,
   "accuracy": 0.6243,
   "ci95_low": 0.5739,
   "ci95_high": 0.6722,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_の",
   "label_zh": "助詞「の」",
   "label_en": "Particles – の",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 120,
   "learners": 44,
   "accuracy": 0.8333,
   "ci95_low": 0.7565,
   "ci95_high": 0.8894,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_は",
   "label_zh": "助詞「は」",
   "label_en": "Particles – は",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 20,
   "learners": 13,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_へ",
   "label_zh": "助詞「へ」",
   "label_en": "Particles – へ",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 45,
   "learners": 36,
   "accuracy": 0.9111,
   "ci95_low": 0.7927,
   "ci95_high": 0.9649,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_まで",
   "label_zh": "助詞「まで」",
   "label_en": "Particles – まで",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 55,
   "learners": 31,
   "accuracy": 0.7636,
   "ci95_low": 0.6365,
   "ci95_high": 0.8563,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_も",
   "label_zh": "助詞「も」",
   "label_en": "Particles – も",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 67,
   "learners": 47,
   "accuracy": 0.4328,
   "ci95_low": 0.321,
   "ci95_high": 0.5519,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_より",
   "label_zh": "助詞「より」",
   "label_en": "Particles – より",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 33,
   "learners": 23,
   "accuracy": 0.9394,
   "ci95_low": 0.8039,
   "ci95_high": 0.9832,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_を",
   "label_zh": "助詞「を」",
   "label_en": "Particles – を",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "quiz_first_attempt",
   "n": 385,
   "learners": 61,
   "accuracy": 0.787,
   "ci95_low": 0.7434,
   "ci95_high": 0.825,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N1",
   "label_zh": "句型／文法（N1）",
   "label_en": "Grammar patterns (N1)",
   "category": "pattern",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 1299,
   "learners": 118,
   "accuracy": 0.5704,
   "ci95_low": 0.5434,
   "ci95_high": 0.5971,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N2",
   "label_zh": "句型／文法（N2）",
   "label_en": "Grammar patterns (N2)",
   "category": "pattern",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 1183,
   "learners": 191,
   "accuracy": 0.5131,
   "ci95_low": 0.4846,
   "ci95_high": 0.5415,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N3",
   "label_zh": "句型／文法（N3）",
   "label_en": "Grammar patterns (N3)",
   "category": "pattern",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 2536,
   "learners": 390,
   "accuracy": 0.4925,
   "ci95_low": 0.4731,
   "ci95_high": 0.512,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N4",
   "label_zh": "句型／文法（N4）",
   "label_en": "Grammar patterns (N4)",
   "category": "pattern",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 1746,
   "learners": 234,
   "accuracy": 0.4822,
   "ci95_low": 0.4589,
   "ci95_high": 0.5057,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N5",
   "label_zh": "句型／文法（N5）",
   "label_en": "Grammar patterns (N5)",
   "category": "pattern",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 1963,
   "learners": 209,
   "accuracy": 0.6444,
   "ci95_low": 0.623,
   "ci95_high": 0.6653,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N1",
   "label_zh": "詞彙（N1）",
   "label_en": "Vocabulary (N1)",
   "category": "vocab",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 703,
   "learners": 94,
   "accuracy": 0.8919,
   "ci95_low": 0.8668,
   "ci95_high": 0.9128,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N2",
   "label_zh": "詞彙（N2）",
   "label_en": "Vocabulary (N2)",
   "category": "vocab",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 1098,
   "learners": 152,
   "accuracy": 0.8497,
   "ci95_low": 0.8274,
   "ci95_high": 0.8696,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N3",
   "label_zh": "詞彙（N3）",
   "label_en": "Vocabulary (N3)",
   "category": "vocab",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 2211,
   "learners": 277,
   "accuracy": 0.8403,
   "ci95_low": 0.8245,
   "ci95_high": 0.855,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N4",
   "label_zh": "詞彙（N4）",
   "label_en": "Vocabulary (N4)",
   "category": "vocab",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 2828,
   "learners": 243,
   "accuracy": 0.8904,
   "ci95_low": 0.8783,
   "ci95_high": 0.9014,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N5",
   "label_zh": "詞彙（N5）",
   "label_en": "Vocabulary (N5)",
   "category": "vocab",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 16029,
   "learners": 311,
   "accuracy": 0.9441,
   "ci95_low": 0.9404,
   "ci95_high": 0.9476,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N1",
   "label_zh": "活用變化（N1）",
   "label_en": "Word forms (N1)",
   "category": "wordform",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 296,
   "learners": 79,
   "accuracy": 0.9561,
   "ci95_low": 0.9263,
   "ci95_high": 0.9742,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N2",
   "label_zh": "活用變化（N2）",
   "label_en": "Word forms (N2)",
   "category": "wordform",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 278,
   "learners": 107,
   "accuracy": 0.8022,
   "ci95_low": 0.7513,
   "ci95_high": 0.8447,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N3",
   "label_zh": "活用變化（N3）",
   "label_en": "Word forms (N3)",
   "category": "wordform",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 913,
   "learners": 294,
   "accuracy": 0.7317,
   "ci95_low": 0.702,
   "ci95_high": 0.7594,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N4",
   "label_zh": "活用變化（N4）",
   "label_en": "Word forms (N4)",
   "category": "wordform",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 461,
   "learners": 149,
   "accuracy": 0.8698,
   "ci95_low": 0.8361,
   "ci95_high": 0.8975,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "particle",
   "label_zh": "助詞",
   "label_en": "Particles",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 747,
   "learners": 284,
   "accuracy": 0.7189,
   "ci95_low": 0.6856,
   "ci95_high": 0.7499,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "pattern",
   "label_zh": "句型／文法",
   "label_en": "Grammar patterns",
   "category": "pattern",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 13937,
   "learners": 424,
   "accuracy": 0.8538,
   "ci95_low": 0.8478,
   "ci95_high": 0.8595,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "wordform",
   "label_zh": "活用變化",
   "label_en": "Word forms / conjugation",
   "category": "wordform",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 1057,
   "learners": 90,
   "accuracy": 0.6509,
   "ci95_low": 0.6217,
   "ci95_high": 0.679,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N1",
   "label_zh": "N1",
   "label_en": "N1",
   "category": null,
   "jlpt_level": "N1",
   "analysis_set": "lesson_first_attempt",
   "n": 126,
   "learners": 7,
   "accuracy": 0.8651,
   "ci95_low": 0.7945,
   "ci95_high": 0.914,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N2",
   "label_zh": "N2",
   "label_en": "N2",
   "category": null,
   "jlpt_level": "N2",
   "analysis_set": "lesson_first_attempt",
   "n": 260,
   "learners": 27,
   "accuracy": 0.7923,
   "ci95_low": 0.7389,
   "ci95_high": 0.8372,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N3",
   "label_zh": "N3",
   "label_en": "N3",
   "category": null,
   "jlpt_level": "N3",
   "analysis_set": "lesson_first_attempt",
   "n": 1507,
   "learners": 126,
   "accuracy": 0.8208,
   "ci95_low": 0.8007,
   "ci95_high": 0.8394,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N4",
   "label_zh": "N4",
   "label_en": "N4",
   "category": null,
   "jlpt_level": "N4",
   "analysis_set": "lesson_first_attempt",
   "n": 2694,
   "learners": 91,
   "accuracy": 0.8307,
   "ci95_low": 0.8161,
   "ci95_high": 0.8444,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N5",
   "label_zh": "N5",
   "label_en": "N5",
   "category": null,
   "jlpt_level": "N5",
   "analysis_set": "lesson_first_attempt",
   "n": 11154,
   "learners": 526,
   "accuracy": 0.8368,
   "ci95_low": 0.8299,
   "ci95_high": 0.8436,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_masu",
   "label_zh": "動詞活用「masu」",
   "label_en": "Verb conjugation – masu",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 117,
   "learners": 28,
   "accuracy": 0.8462,
   "ci95_low": 0.7699,
   "ci95_high": 0.9004,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_nai",
   "label_zh": "動詞活用「nai」",
   "label_en": "Verb conjugation – nai",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 155,
   "learners": 29,
   "accuracy": 0.6065,
   "ci95_low": 0.5279,
   "ci95_high": 0.6799,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_potential",
   "label_zh": "動詞活用「potential」",
   "label_en": "Verb conjugation – potential",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 89,
   "learners": 24,
   "accuracy": 0.2697,
   "ci95_low": 0.1884,
   "ci95_high": 0.37,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_ta",
   "label_zh": "動詞活用「ta」",
   "label_en": "Verb conjugation – ta",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 153,
   "learners": 25,
   "accuracy": 0.5686,
   "ci95_low": 0.4894,
   "ci95_high": 0.6445,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_te",
   "label_zh": "動詞活用「te」",
   "label_en": "Verb conjugation – te",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 218,
   "learners": 28,
   "accuracy": 0.6284,
   "ci95_low": 0.5626,
   "ci95_high": 0.6898,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_other",
   "label_zh": "助詞「other」",
   "label_en": "Particles – other",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 444,
   "learners": 73,
   "accuracy": 0.759,
   "ci95_low": 0.7171,
   "ci95_high": 0.7965,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_が",
   "label_zh": "助詞「が」",
   "label_en": "Particles – が",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 133,
   "learners": 124,
   "accuracy": 0.6541,
   "ci95_low": 0.57,
   "ci95_high": 0.7296,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_で",
   "label_zh": "助詞「で」",
   "label_en": "Particles – で",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 52,
   "learners": 50,
   "accuracy": 0.7692,
   "ci95_low": 0.6387,
   "ci95_high": 0.8628,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_の",
   "label_zh": "助詞「の」",
   "label_en": "Particles – の",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 9,
   "learners": 9,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_も",
   "label_zh": "助詞「も」",
   "label_en": "Particles – も",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 65,
   "learners": 65,
   "accuracy": 0.4154,
   "ci95_low": 0.3036,
   "ci95_high": 0.5366,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_を",
   "label_zh": "助詞「を」",
   "label_en": "Particles – を",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "lesson_first_attempt",
   "n": 44,
   "learners": 44,
   "accuracy": 0.8409,
   "ci95_low": 0.7063,
   "ci95_high": 0.9207,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N1",
   "label_zh": "句型／文法（N1）",
   "label_en": "Grammar patterns (N1)",
   "category": "pattern",
   "jlpt_level": "N1",
   "analysis_set": "lesson_first_attempt",
   "n": 126,
   "learners": 7,
   "accuracy": 0.8651,
   "ci95_low": 0.7945,
   "ci95_high": 0.914,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N2",
   "label_zh": "句型／文法（N2）",
   "label_en": "Grammar patterns (N2)",
   "category": "pattern",
   "jlpt_level": "N2",
   "analysis_set": "lesson_first_attempt",
   "n": 260,
   "learners": 27,
   "accuracy": 0.7923,
   "ci95_low": 0.7389,
   "ci95_high": 0.8372,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N3",
   "label_zh": "句型／文法（N3）",
   "label_en": "Grammar patterns (N3)",
   "category": "pattern",
   "jlpt_level": "N3",
   "analysis_set": "lesson_first_attempt",
   "n": 1002,
   "learners": 53,
   "accuracy": 0.8603,
   "ci95_low": 0.8374,
   "ci95_high": 0.8804,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N4",
   "label_zh": "句型／文法（N4）",
   "label_en": "Grammar patterns (N4)",
   "category": "pattern",
   "jlpt_level": "N4",
   "analysis_set": "lesson_first_attempt",
   "n": 2353,
   "learners": 56,
   "accuracy": 0.8593,
   "ci95_low": 0.8447,
   "ci95_high": 0.8728,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N5",
   "label_zh": "句型／文法（N5）",
   "label_en": "Grammar patterns (N5)",
   "category": "pattern",
   "jlpt_level": "N5",
   "analysis_set": "lesson_first_attempt",
   "n": 10196,
   "learners": 341,
   "accuracy": 0.8533,
   "ci95_low": 0.8463,
   "ci95_high": 0.86,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N3",
   "label_zh": "活用變化（N3）",
   "label_en": "Word forms (N3)",
   "category": "wordform",
   "jlpt_level": "N3",
   "analysis_set": "lesson_first_attempt",
   "n": 145,
   "learners": 27,
   "accuracy": 0.8069,
   "ci95_low": 0.7351,
   "ci95_high": 0.8629,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N4",
   "label_zh": "活用變化（N4）",
   "label_en": "Word forms (N4)",
   "category": "wordform",
   "jlpt_level": "N4",
   "analysis_set": "lesson_first_attempt",
   "n": 53,
   "learners": 11,
   "accuracy": 0.7358,
   "ci95_low": 0.6042,
   "ci95_high": 0.8356,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N5",
   "label_zh": "活用變化（N5）",
   "label_en": "Word forms (N5)",
   "category": "wordform",
   "jlpt_level": "N5",
   "analysis_set": "lesson_first_attempt",
   "n": 127,
   "learners": 24,
   "accuracy": 0.7165,
   "ci95_low": 0.6327,
   "ci95_high": 0.7877,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "allround",
   "label_zh": "綜合",
   "label_en": "Mixed / all-round",
   "category": "allround",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 27,
   "learners": 8,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis",
   "key": "idiom",
   "label_zh": "慣用表現",
   "label_en": "Idiomatic expressions",
   "category": "idiom",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 1344,
   "learners": 261,
   "accuracy": 0.8646,
   "ci95_low": 0.8452,
   "ci95_high": 0.8818,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "particle",
   "label_zh": "助詞",
   "label_en": "Particles",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 2627,
   "learners": 379,
   "accuracy": 0.697,
   "ci95_low": 0.6791,
   "ci95_high": 0.7143,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "pattern",
   "label_zh": "句型／文法",
   "label_en": "Grammar patterns",
   "category": "pattern",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 22638,
   "learners": 816,
   "accuracy": 0.7323,
   "ci95_low": 0.7265,
   "ci95_high": 0.738,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "reading",
   "label_zh": "讀解",
   "label_en": "Reading comprehension",
   "category": "reading",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 24,
   "learners": 4,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis",
   "key": "vocab",
   "label_zh": "詞彙",
   "label_en": "Vocabulary",
   "category": "vocab",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 22891,
   "learners": 627,
   "accuracy": 0.9214,
   "ci95_low": 0.9178,
   "ci95_high": 0.9248,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "wordform",
   "label_zh": "活用變化",
   "label_en": "Word forms / conjugation",
   "category": "wordform",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 3383,
   "learners": 450,
   "accuracy": 0.7759,
   "ci95_low": 0.7616,
   "ci95_high": 0.7897,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N1",
   "label_zh": "N1",
   "label_en": "N1",
   "category": null,
   "jlpt_level": "N1",
   "analysis_set": "first_attempt",
   "n": 3174,
   "learners": 141,
   "accuracy": 0.7637,
   "ci95_low": 0.7486,
   "ci95_high": 0.7782,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N2",
   "label_zh": "N2",
   "label_en": "N2",
   "category": null,
   "jlpt_level": "N2",
   "analysis_set": "first_attempt",
   "n": 2985,
   "learners": 226,
   "accuracy": 0.7025,
   "ci95_low": 0.6859,
   "ci95_high": 0.7186,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N3",
   "label_zh": "N3",
   "label_en": "N3",
   "category": null,
   "jlpt_level": "N3",
   "analysis_set": "first_attempt",
   "n": 7522,
   "learners": 512,
   "accuracy": 0.7078,
   "ci95_low": 0.6974,
   "ci95_high": 0.718,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N4",
   "label_zh": "N4",
   "label_en": "N4",
   "category": null,
   "jlpt_level": "N4",
   "analysis_set": "first_attempt",
   "n": 8758,
   "learners": 379,
   "accuracy": 0.7654,
   "ci95_low": 0.7564,
   "ci95_high": 0.7741,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N5",
   "label_zh": "N5",
   "label_en": "N5",
   "category": null,
   "jlpt_level": "N5",
   "analysis_set": "first_attempt",
   "n": 30495,
   "learners": 764,
   "accuracy": 0.8783,
   "ci95_low": 0.8746,
   "ci95_high": 0.882,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_masu",
   "label_zh": "動詞活用「masu」",
   "label_en": "Verb conjugation – masu",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 171,
   "learners": 44,
   "accuracy": 0.8889,
   "ci95_low": 0.833,
   "ci95_high": 0.9277,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_nai",
   "label_zh": "動詞活用「nai」",
   "label_en": "Verb conjugation – nai",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 241,
   "learners": 47,
   "accuracy": 0.7344,
   "ci95_low": 0.6753,
   "ci95_high": 0.7862,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_potential",
   "label_zh": "動詞活用「potential」",
   "label_en": "Verb conjugation – potential",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 145,
   "learners": 41,
   "accuracy": 0.5103,
   "ci95_low": 0.4298,
   "ci95_high": 0.5904,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_ta",
   "label_zh": "動詞活用「ta」",
   "label_en": "Verb conjugation – ta",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 240,
   "learners": 43,
   "accuracy": 0.7125,
   "ci95_low": 0.6522,
   "ci95_high": 0.7661,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_te",
   "label_zh": "動詞活用「te」",
   "label_en": "Verb conjugation – te",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 306,
   "learners": 46,
   "accuracy": 0.7255,
   "ci95_low": 0.6729,
   "ci95_high": 0.7725,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N1",
   "label_zh": "慣用表現（N1）",
   "label_en": "Idioms (N1)",
   "category": "idiom",
   "jlpt_level": "N1",
   "analysis_set": "first_attempt",
   "n": 745,
   "learners": 111,
   "accuracy": 0.8886,
   "ci95_low": 0.864,
   "ci95_high": 0.9092,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N2",
   "label_zh": "慣用表現（N2）",
   "label_en": "Idioms (N2)",
   "category": "idiom",
   "jlpt_level": "N2",
   "analysis_set": "first_attempt",
   "n": 167,
   "learners": 62,
   "accuracy": 0.7665,
   "ci95_low": 0.6968,
   "ci95_high": 0.8242,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N3",
   "label_zh": "慣用表現（N3）",
   "label_en": "Idioms (N3)",
   "category": "idiom",
   "jlpt_level": "N3",
   "analysis_set": "first_attempt",
   "n": 290,
   "learners": 142,
   "accuracy": 0.8586,
   "ci95_low": 0.8138,
   "ci95_high": 0.894,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N4",
   "label_zh": "慣用表現（N4）",
   "label_en": "Idioms (N4)",
   "category": "idiom",
   "jlpt_level": "N4",
   "analysis_set": "first_attempt",
   "n": 140,
   "learners": 91,
   "accuracy": 0.8643,
   "ci95_low": 0.7977,
   "ci95_high": 0.9114,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N5",
   "label_zh": "慣用表現（N5）",
   "label_en": "Idioms (N5)",
   "category": "idiom",
   "jlpt_level": "N5",
   "analysis_set": "first_attempt",
   "n": 2,
   "learners": 2,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_other",
   "label_zh": "助詞「other」",
   "label_en": "Particles – other",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 476,
   "learners": 95,
   "accuracy": 0.7542,
   "ci95_low": 0.7136,
   "ci95_high": 0.7907,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_か",
   "label_zh": "助詞「か」",
   "label_en": "Particles – か",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 14,
   "learners": 14,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_から",
   "label_zh": "助詞「から」",
   "label_en": "Particles – から",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 50,
   "learners": 33,
   "accuracy": 0.62,
   "ci95_low": 0.4815,
   "ci95_high": 0.7414,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_が",
   "label_zh": "助詞「が」",
   "label_en": "Particles – が",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 474,
   "learners": 190,
   "accuracy": 0.6181,
   "ci95_low": 0.5736,
   "ci95_high": 0.6608,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_で",
   "label_zh": "助詞「で」",
   "label_en": "Particles – で",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 370,
   "learners": 129,
   "accuracy": 0.6568,
   "ci95_low": 0.607,
   "ci95_high": 0.7033,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_と",
   "label_zh": "助詞「と」",
   "label_en": "Particles – と",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 94,
   "learners": 46,
   "accuracy": 0.8298,
   "ci95_low": 0.7413,
   "ci95_high": 0.8924,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_に",
   "label_zh": "助詞「に」",
   "label_en": "Particles – に",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 347,
   "learners": 75,
   "accuracy": 0.6254,
   "ci95_low": 0.5733,
   "ci95_high": 0.6747,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_の",
   "label_zh": "助詞「の」",
   "label_en": "Particles – の",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 122,
   "learners": 51,
   "accuracy": 0.8443,
   "ci95_low": 0.7695,
   "ci95_high": 0.898,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_は",
   "label_zh": "助詞「は」",
   "label_en": "Particles – は",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 20,
   "learners": 13,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_へ",
   "label_zh": "助詞「へ」",
   "label_en": "Particles – へ",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 43,
   "learners": 36,
   "accuracy": 0.907,
   "ci95_low": 0.784,
   "ci95_high": 0.9632,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_まで",
   "label_zh": "助詞「まで」",
   "label_en": "Particles – まで",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 49,
   "learners": 31,
   "accuracy": 0.7551,
   "ci95_low": 0.6191,
   "ci95_high": 0.854,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_も",
   "label_zh": "助詞「も」",
   "label_en": "Particles – も",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 130,
   "learners": 108,
   "accuracy": 0.4154,
   "ci95_low": 0.3343,
   "ci95_high": 0.5013,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_より",
   "label_zh": "助詞「より」",
   "label_en": "Particles – より",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 29,
   "learners": 23,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_を",
   "label_zh": "助詞「を」",
   "label_en": "Particles – を",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "first_attempt",
   "n": 409,
   "learners": 101,
   "accuracy": 0.7946,
   "ci95_low": 0.7528,
   "ci95_high": 0.8309,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N1",
   "label_zh": "句型／文法（N1）",
   "label_en": "Grammar patterns (N1)",
   "category": "pattern",
   "jlpt_level": "N1",
   "analysis_set": "first_attempt",
   "n": 1429,
   "learners": 120,
   "accuracy": 0.5955,
   "ci95_low": 0.5699,
   "ci95_high": 0.6207,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N2",
   "label_zh": "句型／文法（N2）",
   "label_en": "Grammar patterns (N2)",
   "category": "pattern",
   "jlpt_level": "N2",
   "analysis_set": "first_attempt",
   "n": 1441,
   "learners": 205,
   "accuracy": 0.5635,
   "ci95_low": 0.5378,
   "ci95_high": 0.5889,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N3",
   "label_zh": "句型／文法（N3）",
   "label_en": "Grammar patterns (N3)",
   "category": "pattern",
   "jlpt_level": "N3",
   "analysis_set": "first_attempt",
   "n": 3539,
   "learners": 424,
   "accuracy": 0.5965,
   "ci95_low": 0.5802,
   "ci95_high": 0.6125,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N4",
   "label_zh": "句型／文法（N4）",
   "label_en": "Grammar patterns (N4)",
   "category": "pattern",
   "jlpt_level": "N4",
   "analysis_set": "first_attempt",
   "n": 4099,
   "learners": 280,
   "accuracy": 0.6992,
   "ci95_low": 0.685,
   "ci95_high": 0.713,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N5",
   "label_zh": "句型／文法（N5）",
   "label_en": "Grammar patterns (N5)",
   "category": "pattern",
   "jlpt_level": "N5",
   "analysis_set": "first_attempt",
   "n": 12181,
   "learners": 488,
   "accuracy": 0.8196,
   "ci95_low": 0.8127,
   "ci95_high": 0.8264,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N1",
   "label_zh": "詞彙（N1）",
   "label_en": "Vocabulary (N1)",
   "category": "vocab",
   "jlpt_level": "N1",
   "analysis_set": "first_attempt",
   "n": 704,
   "learners": 94,
   "accuracy": 0.892,
   "ci95_low": 0.867,
   "ci95_high": 0.9129,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N2",
   "label_zh": "詞彙（N2）",
   "label_en": "Vocabulary (N2)",
   "category": "vocab",
   "jlpt_level": "N2",
   "analysis_set": "first_attempt",
   "n": 1099,
   "learners": 152,
   "accuracy": 0.8499,
   "ci95_low": 0.8275,
   "ci95_high": 0.8698,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N3",
   "label_zh": "詞彙（N3）",
   "label_en": "Vocabulary (N3)",
   "category": "vocab",
   "jlpt_level": "N3",
   "analysis_set": "first_attempt",
   "n": 2239,
   "learners": 277,
   "accuracy": 0.8419,
   "ci95_low": 0.8262,
   "ci95_high": 0.8564,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N4",
   "label_zh": "詞彙（N4）",
   "label_en": "Vocabulary (N4)",
   "category": "vocab",
   "jlpt_level": "N4",
   "analysis_set": "first_attempt",
   "n": 2838,
   "learners": 243,
   "accuracy": 0.8908,
   "ci95_low": 0.8788,
   "ci95_high": 0.9017,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N5",
   "label_zh": "詞彙（N5）",
   "label_en": "Vocabulary (N5)",
   "category": "vocab",
   "jlpt_level": "N5",
   "analysis_set": "first_attempt",
   "n": 16011,
   "learners": 311,
   "accuracy": 0.9441,
   "ci95_low": 0.9404,
   "ci95_high": 0.9476,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N1",
   "label_zh": "活用變化（N1）",
   "label_en": "Word forms (N1)",
   "category": "wordform",
   "jlpt_level": "N1",
   "analysis_set": "first_attempt",
   "n": 296,
   "learners": 79,
   "accuracy": 0.9561,
   "ci95_low": 0.9263,
   "ci95_high": 0.9742,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N2",
   "label_zh": "活用變化（N2）",
   "label_en": "Word forms (N2)",
   "category": "wordform",
   "jlpt_level": "N2",
   "analysis_set": "first_attempt",
   "n": 278,
   "learners": 107,
   "accuracy": 0.8022,
   "ci95_low": 0.7513,
   "ci95_high": 0.8447,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N3",
   "label_zh": "活用變化（N3）",
   "label_en": "Word forms (N3)",
   "category": "wordform",
   "jlpt_level": "N3",
   "analysis_set": "first_attempt",
   "n": 1059,
   "learners": 317,
   "accuracy": 0.7422,
   "ci95_low": 0.715,
   "ci95_high": 0.7676,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N4",
   "label_zh": "活用變化（N4）",
   "label_en": "Word forms (N4)",
   "category": "wordform",
   "jlpt_level": "N4",
   "analysis_set": "first_attempt",
   "n": 520,
   "learners": 159,
   "accuracy": 0.8577,
   "ci95_low": 0.825,
   "ci95_high": 0.8851,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N5",
   "label_zh": "活用變化（N5）",
   "label_en": "Word forms (N5)",
   "category": "wordform",
   "jlpt_level": "N5",
   "analysis_set": "first_attempt",
   "n": 127,
   "learners": 24,
   "accuracy": 0.7165,
   "ci95_low": 0.6327,
   "ci95_high": 0.7877,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "allround",
   "label_zh": "綜合",
   "label_en": "Mixed / all-round",
   "category": "allround",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 27,
   "learners": 8,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis",
   "key": "idiom",
   "label_zh": "慣用表現",
   "label_en": "Idiomatic expressions",
   "category": "idiom",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 1380,
   "learners": 261,
   "accuracy": 0.8652,
   "ci95_low": 0.8462,
   "ci95_high": 0.8822,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "particle",
   "label_zh": "助詞",
   "label_en": "Particles",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 3096,
   "learners": 379,
   "accuracy": 0.7148,
   "ci95_low": 0.6986,
   "ci95_high": 0.7304,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "pattern",
   "label_zh": "句型／文法",
   "label_en": "Grammar patterns",
   "category": "pattern",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 24293,
   "learners": 816,
   "accuracy": 0.741,
   "ci95_low": 0.7354,
   "ci95_high": 0.7465,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "reading",
   "label_zh": "讀解",
   "label_en": "Reading comprehension",
   "category": "reading",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 24,
   "learners": 4,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis",
   "key": "vocab",
   "label_zh": "詞彙",
   "label_en": "Vocabulary",
   "category": "vocab",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 24282,
   "learners": 627,
   "accuracy": 0.924,
   "ci95_low": 0.9206,
   "ci95_high": 0.9272,
   "flag": "OK"
  },
  {
   "dimension": "axis",
   "key": "wordform",
   "label_zh": "活用變化",
   "label_en": "Word forms / conjugation",
   "category": "wordform",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 3511,
   "learners": 450,
   "accuracy": 0.7764,
   "ci95_low": 0.7623,
   "ci95_high": 0.7899,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N1",
   "label_zh": "N1",
   "label_en": "N1",
   "category": null,
   "jlpt_level": "N1",
   "analysis_set": "all_events",
   "n": 3266,
   "learners": 141,
   "accuracy": 0.7652,
   "ci95_low": 0.7503,
   "ci95_high": 0.7794,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N2",
   "label_zh": "N2",
   "label_en": "N2",
   "category": null,
   "jlpt_level": "N2",
   "analysis_set": "all_events",
   "n": 3072,
   "learners": 226,
   "accuracy": 0.7054,
   "ci95_low": 0.689,
   "ci95_high": 0.7213,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N3",
   "label_zh": "N3",
   "label_en": "N3",
   "category": null,
   "jlpt_level": "N3",
   "analysis_set": "all_events",
   "n": 7727,
   "learners": 512,
   "accuracy": 0.7108,
   "ci95_low": 0.7005,
   "ci95_high": 0.7208,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N4",
   "label_zh": "N4",
   "label_en": "N4",
   "category": null,
   "jlpt_level": "N4",
   "analysis_set": "all_events",
   "n": 9262,
   "learners": 379,
   "accuracy": 0.7661,
   "ci95_low": 0.7574,
   "ci95_high": 0.7747,
   "flag": "OK"
  },
  {
   "dimension": "jlpt",
   "key": "N5",
   "label_zh": "N5",
   "label_en": "N5",
   "category": null,
   "jlpt_level": "N5",
   "analysis_set": "all_events",
   "n": 33286,
   "learners": 764,
   "accuracy": 0.8821,
   "ci95_low": 0.8786,
   "ci95_high": 0.8856,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_masu",
   "label_zh": "動詞活用「masu」",
   "label_en": "Verb conjugation – masu",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 181,
   "learners": 44,
   "accuracy": 0.895,
   "ci95_low": 0.8419,
   "ci95_high": 0.9318,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_nai",
   "label_zh": "動詞活用「nai」",
   "label_en": "Verb conjugation – nai",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 256,
   "learners": 47,
   "accuracy": 0.7461,
   "ci95_low": 0.6894,
   "ci95_high": 0.7955,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_potential",
   "label_zh": "動詞活用「potential」",
   "label_en": "Verb conjugation – potential",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 151,
   "learners": 41,
   "accuracy": 0.4967,
   "ci95_low": 0.418,
   "ci95_high": 0.5755,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_ta",
   "label_zh": "動詞活用「ta」",
   "label_en": "Verb conjugation – ta",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 253,
   "learners": 43,
   "accuracy": 0.6957,
   "ci95_low": 0.6364,
   "ci95_high": 0.7491,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_conj_te",
   "label_zh": "動詞活用「te」",
   "label_en": "Verb conjugation – te",
   "category": "conj",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 348,
   "learners": 46,
   "accuracy": 0.7328,
   "ci95_low": 0.6839,
   "ci95_high": 0.7765,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N1",
   "label_zh": "慣用表現（N1）",
   "label_en": "Idioms (N1)",
   "category": "idiom",
   "jlpt_level": "N1",
   "analysis_set": "all_events",
   "n": 767,
   "learners": 111,
   "accuracy": 0.8892,
   "ci95_low": 0.865,
   "ci95_high": 0.9095,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N2",
   "label_zh": "慣用表現（N2）",
   "label_en": "Idioms (N2)",
   "category": "idiom",
   "jlpt_level": "N2",
   "analysis_set": "all_events",
   "n": 172,
   "learners": 62,
   "accuracy": 0.7733,
   "ci95_low": 0.7051,
   "ci95_high": 0.8295,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N3",
   "label_zh": "慣用表現（N3）",
   "label_en": "Idioms (N3)",
   "category": "idiom",
   "jlpt_level": "N3",
   "analysis_set": "all_events",
   "n": 295,
   "learners": 142,
   "accuracy": 0.8576,
   "ci95_low": 0.8131,
   "ci95_high": 0.8929,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N4",
   "label_zh": "慣用表現（N4）",
   "label_en": "Idioms (N4)",
   "category": "idiom",
   "jlpt_level": "N4",
   "analysis_set": "all_events",
   "n": 144,
   "learners": 91,
   "accuracy": 0.8611,
   "ci95_low": 0.7952,
   "ci95_high": 0.9083,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_idiom_bucket_N5",
   "label_zh": "慣用表現（N5）",
   "label_en": "Idioms (N5)",
   "category": "idiom",
   "jlpt_level": "N5",
   "analysis_set": "all_events",
   "n": 2,
   "learners": 2,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_other",
   "label_zh": "助詞「other」",
   "label_en": "Particles – other",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 534,
   "learners": 95,
   "accuracy": 0.764,
   "ci95_low": 0.7262,
   "ci95_high": 0.7981,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_か",
   "label_zh": "助詞「か」",
   "label_en": "Particles – か",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 22,
   "learners": 14,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_から",
   "label_zh": "助詞「から」",
   "label_en": "Particles – から",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 58,
   "learners": 33,
   "accuracy": 0.6724,
   "ci95_low": 0.5442,
   "ci95_high": 0.7792,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_が",
   "label_zh": "助詞「が」",
   "label_en": "Particles – が",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 546,
   "learners": 190,
   "accuracy": 0.641,
   "ci95_low": 0.5999,
   "ci95_high": 0.6801,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_で",
   "label_zh": "助詞「で」",
   "label_en": "Particles – で",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 428,
   "learners": 129,
   "accuracy": 0.6729,
   "ci95_low": 0.6271,
   "ci95_high": 0.7156,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_と",
   "label_zh": "助詞「と」",
   "label_en": "Particles – と",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 115,
   "learners": 46,
   "accuracy": 0.8435,
   "ci95_low": 0.7661,
   "ci95_high": 0.8986,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_に",
   "label_zh": "助詞「に」",
   "label_en": "Particles – に",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 435,
   "learners": 75,
   "accuracy": 0.646,
   "ci95_low": 0.5999,
   "ci95_high": 0.6895,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_の",
   "label_zh": "助詞「の」",
   "label_en": "Particles – の",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 155,
   "learners": 51,
   "accuracy": 0.8516,
   "ci95_low": 0.7872,
   "ci95_high": 0.899,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_は",
   "label_zh": "助詞「は」",
   "label_en": "Particles – は",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 21,
   "learners": 13,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_へ",
   "label_zh": "助詞「へ」",
   "label_en": "Particles – へ",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 50,
   "learners": 36,
   "accuracy": 0.92,
   "ci95_low": 0.8116,
   "ci95_high": 0.9685,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_まで",
   "label_zh": "助詞「まで」",
   "label_en": "Particles – まで",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 59,
   "learners": 31,
   "accuracy": 0.7627,
   "ci95_low": 0.6402,
   "ci95_high": 0.8531,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_も",
   "label_zh": "助詞「も」",
   "label_en": "Particles – も",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 142,
   "learners": 108,
   "accuracy": 0.4366,
   "ci95_low": 0.3578,
   "ci95_high": 0.5188,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_より",
   "label_zh": "助詞「より」",
   "label_en": "Particles – より",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 39,
   "learners": 23,
   "accuracy": 0.9487,
   "ci95_low": 0.8311,
   "ci95_high": 0.9858,
   "flag": "LOW_SAMPLE"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_particle_を",
   "label_zh": "助詞「を」",
   "label_en": "Particles – を",
   "category": "particle",
   "jlpt_level": null,
   "analysis_set": "all_events",
   "n": 492,
   "learners": 101,
   "accuracy": 0.8028,
   "ci95_low": 0.7654,
   "ci95_high": 0.8356,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N1",
   "label_zh": "句型／文法（N1）",
   "label_en": "Grammar patterns (N1)",
   "category": "pattern",
   "jlpt_level": "N1",
   "analysis_set": "all_events",
   "n": 1480,
   "learners": 120,
   "accuracy": 0.5993,
   "ci95_low": 0.5741,
   "ci95_high": 0.624,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N2",
   "label_zh": "句型／文法（N2）",
   "label_en": "Grammar patterns (N2)",
   "category": "pattern",
   "jlpt_level": "N2",
   "analysis_set": "all_events",
   "n": 1513,
   "learners": 205,
   "accuracy": 0.573,
   "ci95_low": 0.548,
   "ci95_high": 0.5977,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N3",
   "label_zh": "句型／文法（N3）",
   "label_en": "Grammar patterns (N3)",
   "category": "pattern",
   "jlpt_level": "N3",
   "analysis_set": "all_events",
   "n": 3659,
   "learners": 424,
   "accuracy": 0.6037,
   "ci95_low": 0.5878,
   "ci95_high": 0.6194,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N4",
   "label_zh": "句型／文法（N4）",
   "label_en": "Grammar patterns (N4)",
   "category": "pattern",
   "jlpt_level": "N4",
   "analysis_set": "all_events",
   "n": 4349,
   "learners": 280,
   "accuracy": 0.7054,
   "ci95_low": 0.6917,
   "ci95_high": 0.7188,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_pattern_bucket_N5",
   "label_zh": "句型／文法（N5）",
   "label_en": "Grammar patterns (N5)",
   "category": "pattern",
   "jlpt_level": "N5",
   "analysis_set": "all_events",
   "n": 13343,
   "learners": 488,
   "accuracy": 0.8257,
   "ci95_low": 0.8191,
   "ci95_high": 0.832,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N1",
   "label_zh": "詞彙（N1）",
   "label_en": "Vocabulary (N1)",
   "category": "vocab",
   "jlpt_level": "N1",
   "analysis_set": "all_events",
   "n": 715,
   "learners": 94,
   "accuracy": 0.8937,
   "ci95_low": 0.869,
   "ci95_high": 0.9142,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N2",
   "label_zh": "詞彙（N2）",
   "label_en": "Vocabulary (N2)",
   "category": "vocab",
   "jlpt_level": "N2",
   "analysis_set": "all_events",
   "n": 1104,
   "learners": 152,
   "accuracy": 0.8505,
   "ci95_low": 0.8283,
   "ci95_high": 0.8704,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N3",
   "label_zh": "詞彙（N3）",
   "label_en": "Vocabulary (N3)",
   "category": "vocab",
   "jlpt_level": "N3",
   "analysis_set": "all_events",
   "n": 2257,
   "learners": 277,
   "accuracy": 0.8427,
   "ci95_low": 0.8271,
   "ci95_high": 0.8571,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N4",
   "label_zh": "詞彙（N4）",
   "label_en": "Vocabulary (N4)",
   "category": "vocab",
   "jlpt_level": "N4",
   "analysis_set": "all_events",
   "n": 2864,
   "learners": 243,
   "accuracy": 0.8918,
   "ci95_low": 0.8799,
   "ci95_high": 0.9026,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_vocab_bucket_N5",
   "label_zh": "詞彙（N5）",
   "label_en": "Vocabulary (N5)",
   "category": "vocab",
   "jlpt_level": "N5",
   "analysis_set": "all_events",
   "n": 17342,
   "learners": 311,
   "accuracy": 0.9458,
   "ci95_low": 0.9423,
   "ci95_high": 0.9491,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N1",
   "label_zh": "活用變化（N1）",
   "label_en": "Word forms (N1)",
   "category": "wordform",
   "jlpt_level": "N1",
   "analysis_set": "all_events",
   "n": 304,
   "learners": 79,
   "accuracy": 0.9572,
   "ci95_low": 0.9282,
   "ci95_high": 0.9748,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N2",
   "label_zh": "活用變化（N2）",
   "label_en": "Word forms (N2)",
   "category": "wordform",
   "jlpt_level": "N2",
   "analysis_set": "all_events",
   "n": 283,
   "learners": 107,
   "accuracy": 0.8057,
   "ci95_low": 0.7556,
   "ci95_high": 0.8475,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N3",
   "label_zh": "活用變化（N3）",
   "label_en": "Word forms (N3)",
   "category": "wordform",
   "jlpt_level": "N3",
   "analysis_set": "all_events",
   "n": 1069,
   "learners": 317,
   "accuracy": 0.7428,
   "ci95_low": 0.7157,
   "ci95_high": 0.7681,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N4",
   "label_zh": "活用變化（N4）",
   "label_en": "Word forms (N4)",
   "category": "wordform",
   "jlpt_level": "N4",
   "analysis_set": "all_events",
   "n": 526,
   "learners": 159,
   "accuracy": 0.8593,
   "ci95_low": 0.827,
   "ci95_high": 0.8864,
   "flag": "OK"
  },
  {
   "dimension": "knowledge_point",
   "key": "kp_wordform_bucket_N5",
   "label_zh": "活用變化（N5）",
   "label_en": "Word forms (N5)",
   "category": "wordform",
   "jlpt_level": "N5",
   "analysis_set": "all_events",
   "n": 140,
   "learners": 24,
   "accuracy": 0.7286,
   "ci95_low": 0.6495,
   "ci95_high": 0.7954,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "allround|N1",
   "label_zh": "綜合 × N1",
   "label_en": "Mixed / all-round × N1",
   "category": "allround",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 4,
   "learners": 1,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "allround|N2",
   "label_zh": "綜合 × N2",
   "label_en": "Mixed / all-round × N2",
   "category": "allround",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 4,
   "learners": 2,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "allround|N3",
   "label_zh": "綜合 × N3",
   "label_en": "Mixed / all-round × N3",
   "category": "allround",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 5,
   "learners": 2,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "allround|N4",
   "label_zh": "綜合 × N4",
   "label_en": "Mixed / all-round × N4",
   "category": "allround",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 8,
   "learners": 2,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "allround|N5",
   "label_zh": "綜合 × N5",
   "label_en": "Mixed / all-round × N5",
   "category": "allround",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 6,
   "learners": 1,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "idiom|N1",
   "label_zh": "慣用表現 × N1",
   "label_en": "Idiomatic expressions × N1",
   "category": "idiom",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 742,
   "learners": 111,
   "accuracy": 0.8881,
   "ci95_low": 0.8634,
   "ci95_high": 0.9089,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "idiom|N2",
   "label_zh": "慣用表現 × N2",
   "label_en": "Idiomatic expressions × N2",
   "category": "idiom",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 167,
   "learners": 62,
   "accuracy": 0.7665,
   "ci95_low": 0.6968,
   "ci95_high": 0.8242,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "idiom|N3",
   "label_zh": "慣用表現 × N3",
   "label_en": "Idiomatic expressions × N3",
   "category": "idiom",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 290,
   "learners": 142,
   "accuracy": 0.8586,
   "ci95_low": 0.8138,
   "ci95_high": 0.894,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "idiom|N4",
   "label_zh": "慣用表現 × N4",
   "label_en": "Idiomatic expressions × N4",
   "category": "idiom",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 140,
   "learners": 91,
   "accuracy": 0.8643,
   "ci95_low": 0.7977,
   "ci95_high": 0.9114,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "idiom|N5",
   "label_zh": "慣用表現 × N5",
   "label_en": "Idiomatic expressions × N5",
   "category": "idiom",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 2,
   "learners": 2,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "particle|N4",
   "label_zh": "助詞 × N4",
   "label_en": "Particles × N4",
   "category": "particle",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 766,
   "learners": 92,
   "accuracy": 0.5849,
   "ci95_low": 0.5496,
   "ci95_high": 0.6192,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "particle|N5",
   "label_zh": "助詞 × N5",
   "label_en": "Particles × N5",
   "category": "particle",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 1220,
   "learners": 111,
   "accuracy": 0.7582,
   "ci95_low": 0.7334,
   "ci95_high": 0.7814,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "pattern|N1",
   "label_zh": "句型／文法 × N1",
   "label_en": "Grammar patterns × N1",
   "category": "pattern",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 1295,
   "learners": 118,
   "accuracy": 0.5699,
   "ci95_low": 0.5428,
   "ci95_high": 0.5966,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "pattern|N2",
   "label_zh": "句型／文法 × N2",
   "label_en": "Grammar patterns × N2",
   "category": "pattern",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 1179,
   "learners": 191,
   "accuracy": 0.5115,
   "ci95_low": 0.4829,
   "ci95_high": 0.5399,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "pattern|N3",
   "label_zh": "句型／文法 × N3",
   "label_en": "Grammar patterns × N3",
   "category": "pattern",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 2531,
   "learners": 389,
   "accuracy": 0.4919,
   "ci95_low": 0.4725,
   "ci95_high": 0.5114,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "pattern|N4",
   "label_zh": "句型／文法 × N4",
   "label_en": "Grammar patterns × N4",
   "category": "pattern",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 1734,
   "learners": 233,
   "accuracy": 0.4798,
   "ci95_low": 0.4564,
   "ci95_high": 0.5033,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "pattern|N5",
   "label_zh": "句型／文法 × N5",
   "label_en": "Grammar patterns × N5",
   "category": "pattern",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 1939,
   "learners": 208,
   "accuracy": 0.64,
   "ci95_low": 0.6184,
   "ci95_high": 0.6611,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "reading|N4",
   "label_zh": "讀解 × N4",
   "label_en": "Reading comprehension × N4",
   "category": "reading",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 4,
   "learners": 1,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "reading|N5",
   "label_zh": "讀解 × N5",
   "label_en": "Reading comprehension × N5",
   "category": "reading",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 18,
   "learners": 4,
   "accuracy": null,
   "ci95_low": null,
   "ci95_high": null,
   "flag": "SUPPRESSED"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "vocab|N1",
   "label_zh": "詞彙 × N1",
   "label_en": "Vocabulary × N1",
   "category": "vocab",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 703,
   "learners": 94,
   "accuracy": 0.8919,
   "ci95_low": 0.8668,
   "ci95_high": 0.9128,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "vocab|N2",
   "label_zh": "詞彙 × N2",
   "label_en": "Vocabulary × N2",
   "category": "vocab",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 1098,
   "learners": 152,
   "accuracy": 0.8497,
   "ci95_low": 0.8274,
   "ci95_high": 0.8696,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "vocab|N3",
   "label_zh": "詞彙 × N3",
   "label_en": "Vocabulary × N3",
   "category": "vocab",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 2211,
   "learners": 277,
   "accuracy": 0.8403,
   "ci95_low": 0.8245,
   "ci95_high": 0.855,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "vocab|N4",
   "label_zh": "詞彙 × N4",
   "label_en": "Vocabulary × N4",
   "category": "vocab",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
   "n": 2828,
   "learners": 243,
   "accuracy": 0.8904,
   "ci95_low": 0.8783,
   "ci95_high": 0.9014,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "vocab|N5",
   "label_zh": "詞彙 × N5",
   "label_en": "Vocabulary × N5",
   "category": "vocab",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 16029,
   "learners": 311,
   "accuracy": 0.9441,
   "ci95_low": 0.9404,
   "ci95_high": 0.9476,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "wordform|N1",
   "label_zh": "活用變化 × N1",
   "label_en": "Word forms / conjugation × N1",
   "category": "wordform",
   "jlpt_level": "N1",
   "analysis_set": "quiz_first_attempt",
   "n": 296,
   "learners": 79,
   "accuracy": 0.9561,
   "ci95_low": 0.9263,
   "ci95_high": 0.9742,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "wordform|N2",
   "label_zh": "活用變化 × N2",
   "label_en": "Word forms / conjugation × N2",
   "category": "wordform",
   "jlpt_level": "N2",
   "analysis_set": "quiz_first_attempt",
   "n": 278,
   "learners": 107,
   "accuracy": 0.8022,
   "ci95_low": 0.7513,
   "ci95_high": 0.8447,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "wordform|N3",
   "label_zh": "活用變化 × N3",
   "label_en": "Word forms / conjugation × N3",
   "category": "wordform",
   "jlpt_level": "N3",
   "analysis_set": "quiz_first_attempt",
   "n": 948,
   "learners": 302,
   "accuracy": 0.7416,
   "ci95_low": 0.7128,
   "ci95_high": 0.7684,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "wordform|N4",
   "label_zh": "活用變化 × N4",
   "label_en": "Word forms / conjugation × N4",
   "category": "wordform",
   "jlpt_level": "N4",
   "analysis_set": "quiz_first_attempt",
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   "learners": 167,
   "accuracy": 0.8885,
   "ci95_low": 0.8613,
   "ci95_high": 0.911,
   "flag": "OK"
  },
  {
   "dimension": "axis_x_jlpt",
   "key": "wordform|N5",
   "label_zh": "活用變化 × N5",
   "label_en": "Word forms / conjugation × N5",
   "category": "wordform",
   "jlpt_level": "N5",
   "analysis_set": "quiz_first_attempt",
   "n": 181,
   "learners": 26,
   "accuracy": 0.9613,
   "ci95_low": 0.9223,
   "ci95_high": 0.9811,
   "flag": "OK"
  }
 ]
}