Base Difficulty

Base difficulty: Level 221 edit

Level distribution for noun (concept_idea): 19: 2 26: 1 27: 1 221: 28 270: 30 274: 30 275: 28 280: 25 300: 1 360: 1 380: 2 1000: 1 1030: 1 1060: 5 1070: 6 1110: 4 1120: 4 1399: 66

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: 368 (weighted harmonic mean of corpus + tier signals; lower = more common)
Tier Signals
Source Tier Rank used
basic_english Basic (1 of 2) 600
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 147.95 768 100% 629 2
20th_books 100.96 1103 100% 903 2
wiki_math 261.00 854 100% 503 2
wiki_geography 184.06 1350 100% 760 2
wiki_biology 356.84 723 100% 380 2
wiki_modern_life 527.71 367 100% 219 2
wiki_arts 449.64 497 100% 271 2
wiki_society 432.22 442 100% 278 2
wiki_linguistics 191.32 1041 100% 672 2
wiki_physical_science 1146.86 166 100% 95 2
wiki_history 234.66 841 100% 562 2
early_modern_science 623.44 267 100% 172 2
religious_translated 137.04 1003 100% 734 2
cooking 78.88 1339 100% 1339 1
legal_scotus 776.75 169 100% 138 2
eu_parliament_debates 382.47 538 100% 318 2
openstax_science 668.70 365 100% 189 2
openstax_society 448.09 522 100% 306 2
wpa_life_histories 41.68 2714 100% 1911 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.