Base Difficulty

Base difficulty: Level 276 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: 2369 (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 4.22 4978 20% 15841 downrated 2
20th_books 1.47 7769 20% 20000 capped 1
wiki_math 308.58 83 20% 378 downrated 2
wiki_geography 43.55 882 20% 3109 downrated 2
wiki_biology 53.83 741 20% 2550 downrated 2
wiki_modern_life 134.14 237 20% 783 downrated 2
wiki_arts 32.64 1515 20% 4247 downrated 2
wiki_society 78.20 568 20% 1621 downrated 2
wiki_linguistics 5.91 3502 20% 9000 capped 1
wiki_physical_science 121.04 416 20% 1109 downrated 2
wiki_history 16.49 3019 20% 8163 downrated 2
early_modern_science 37.21 947 20% 3092 downrated 2
religious_translated 0.00 — — — 0
cooking 21.86 1656 20% 4217 downrated 2
legal_scotus 40.96 1074 20% 3182 downrated 2
eu_parliament_debates 100.27 323 20% 1219 downrated 2
openstax_science 108.22 458 20% 1232 downrated 2
openstax_society 83.91 591 20% 1671 downrated 2
wpa_life_histories 5.83 4562 20% 12460 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.