Base Difficulty

Base difficulty: Level 1399 edit

Level distribution for verb (perception): 5: 1 8: 2 185: 1 205: 1 214: 12 230: 1 265: 1 279: 1 455: 1 1040: 1 1399: 4

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: 815 (weighted harmonic mean of corpus + tier signals; lower = more common)
Tier Signals
Source Tier Rank used
basic_english Basic (1 of 2) 600
cefr B1 (3 of 6) 4200

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 98.78 1029 67% 907 3
20th_books 107.46 949 67% 849 3
wiki_math 11.52 3934 67% 5901 downrated 1
wiki_geography 161.99 1235 80% 852 3
wiki_biology 67.90 2348 67% 1953 2
wiki_modern_life 161.21 1022 67% 886 3
wiki_arts 187.21 822 67% 717 3
wiki_society 438.32 293 67% 272 4
wiki_linguistics 63.57 1962 67% 1822 2
wiki_physical_science 117.00 1626 67% 1168 3
wiki_history 177.94 1024 67% 757 3
early_modern_science 112.54 888 67% 989 downrated 2
religious_translated 42.34 2177 67% 2078 2
cooking 32.29 1793 67% 2690 downrated 1
legal_scotus 77.37 1507 67% 1433 3
eu_parliament_debates 195.51 655 67% 544 4
openstax_science 218.91 739 67% 607 4
openstax_society 692.25 221 67% 182 4
wpa_life_histories 105.82 995 67% 856 3

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.