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: 7381 (weighted harmonic mean of corpus + tier signals; lower = more common)
Tier Signals
Source Tier Rank used
basic_english Extended (2 of 2) 1600
cefr A2 (2 of 6) 2100

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 17.21 630 10% 5597 downrated 2
20th_books 13.23 804 10% 7182 downrated 2
wiki_math 51.48 411 10% 2693 downrated 2
wiki_geography 0.00 — — — 0
wiki_biology 6.55 2083 10% 9000 capped 1
wiki_modern_life 5.00 2900 10% 10000 capped 1
wiki_arts 16.99 948 10% 7830 downrated 2
wiki_society 15.65 1205 10% 8822 downrated 2
wiki_linguistics 28.08 877 10% 4650 downrated 2
wiki_physical_science 14.14 1039 10% 8000 capped 1
wiki_history 5.77 2373 10% 9000 capped 1
early_modern_science 8.08 1814 10% 10400 capped 2
religious_translated 3.64 2560 10% 10400 capped 1
cooking 0.00 — — — 0
legal_scotus 11.98 1183 10% 10151 downrated 2
eu_parliament_debates 7.61 1498 10% 11000 capped 1
openstax_science 32.81 473 10% 4013 downrated 2
openstax_society 11.98 1544 10% 10995 downrated 2
wpa_life_histories 4.78 2205 10% 16486 downrated 2

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.