Base Difficulty

Base difficulty: Level 224 edit

Level distribution for noun (unit_of_measurement): 224: 12 1050: 1 1090: 8 1399: 3

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: 657 (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 103.64 1367 100% 870 2
20th_books 44.80 2369 100% 1743 2
wiki_math 584.37 366 100% 238 2
wiki_geography 164.83 1469 100% 852 2
wiki_biology 135.66 1451 100% 1010 2
wiki_modern_life 239.59 995 100% 597 2
wiki_arts 147.35 1444 100% 943 2
wiki_society 425.68 395 100% 279 2
wiki_linguistics 274.08 668 100% 476 2
wiki_physical_science 314.26 917 100% 463 2
wiki_history 162.79 1013 100% 812 2
early_modern_science 564.21 311 100% 191 2
religious_translated 83.81 1621 100% 1146 2
cooking 175.79 940 100% 620 2
legal_scotus 146.53 949 100% 839 2
eu_parliament_debates 90.41 1290 100% 1290 1
openstax_science 140.89 1452 100% 948 2
openstax_society 242.23 736 100% 574 2
wpa_life_histories 33.16 3424 100% 2250 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.