Base Difficulty

Base difficulty: Level 1399 edit

Level distribution for noun (mathematical_concept): 276: 1 280: 1 329: 3 380: 4 1080: 15 1399: 19

Per-Language Difficulty Overrides

No difficulty overrides set. The base difficulty level will be used for all languages.

Add Difficulty Override
-1 to exclude, 1-1399 for level
Frequency and Tier Signals
Combined Frequency Rank: 3902 (weighted harmonic mean of corpus + tier signals; lower = more common)
Tier Signals
Source Tier Rank used
basic_english Extended (2 of 2) 1600
cefr B2 (4 of 6) 6900

Rank used = synthetic rank this tier contributes to the combined frequency rank (lower = more common).

Corpus Frequency
Corpus Freq (per M) Best form Share Zipf rank Forms
19th_books 0.00 — — — 0
20th_books 1.40 7074 17% 20000 capped 1
wiki_math 80.88 589 17% 1694 downrated 2
wiki_geography 19.47 2237 20% 7151 downrated 2
wiki_biology 45.84 886 20% 3005 downrated 2
wiki_modern_life 57.25 749 20% 2411 downrated 2
wiki_arts 14.41 2958 20% 9319 downrated 2
wiki_society 59.15 608 20% 2197 downrated 2
wiki_linguistics 25.64 1269 20% 4823 downrated 2
wiki_physical_science 81.95 592 20% 1725 downrated 2
wiki_history 14.18 3356 20% 9000 capped 2
early_modern_science 0.00 — — — 0
religious_translated 0.00 — — — 0
cooking 0.00 — — — 0
legal_scotus 85.93 461 20% 1469 downrated 2
eu_parliament_debates 25.04 1574 17% 4430 downrated 2
openstax_science 103.64 360 20% 1252 downrated 2
openstax_society 87.29 345 20% 1436 downrated 2
wpa_life_histories 1.68 5992 17% 20000 capped 1

Best form = the single best-ranked form in the corpus, share-blind — how the spelling itself ranked. Share = how much of that spelling belongs to this lemma, when several senses compete for it. Zipf rank = all the forms combined (variant spellings included), each scaled by its share, and what feeds the combined frequency rank. Combining forms improves on the best form, but a share below 100% pushes the other way and usually wins: a sense holding a small slice of a common spelling is a rare word, so its rank lands downrated below the best form — and once it falls past what the corpus can support it is capped at the rank an unlisted word would get.