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: 499 (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 107.60 884 100% 884 1
20th_books 45.85 1912 100% 1912 1
wiki_math 1421.66 162 100% 90 2
wiki_geography 111.42 1814 100% 1249 2
wiki_biology 105.36 1327 100% 1327 1
wiki_modern_life 306.15 629 100% 437 2
wiki_arts 77.97 2894 100% 1733 2
wiki_society 505.79 250 100% 217 2
wiki_linguistics 131.67 1568 100% 948 2
wiki_physical_science 802.98 156 100% 134 2
wiki_history 152.94 1241 100% 875 2
early_modern_science 153.01 1384 100% 757 2
religious_translated 38.33 2444 100% 2444 1
cooking 0.00 — — — 0
legal_scotus 693.57 148 100% 144 2
eu_parliament_debates 53.01 1982 100% 1982 1
openstax_science 316.69 563 100% 433 2
openstax_society 232.31 601 100% 601 1
wpa_life_histories 114.73 900 100% 900 1

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.