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: 257 (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 224.01 512 95% 438 2
20th_books 197.10 587 95% 512 2
wiki_math 551.70 349 95% 258 2
wiki_geography 599.47 209 95% 187 2
wiki_biology 59.35 2194 95% 2304 downrated 1
wiki_modern_life 1124.43 72 95% 74 downrated 2
wiki_arts 263.71 557 95% 483 2
wiki_society 794.32 145 95% 127 2
wiki_linguistics 71.18 1710 95% 1796 downrated 1
wiki_physical_science 403.82 306 95% 321 downrated 1
wiki_history 827.19 133 95% 121 2
early_modern_science 586.97 212 95% 178 2
religious_translated 795.97 183 95% 155 2
cooking 25.75 2585 95% 2714 downrated 1
legal_scotus 794.08 147 95% 132 2
eu_parliament_debates 406.61 453 95% 302 2
openstax_science 279.26 438 95% 460 downrated 1
openstax_society 1189.05 93 95% 88 2
wpa_life_histories 68.85 1449 95% 1295 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.