Evidence-source registry, machine-normalized 2026-08-24. Identity and independence flag are unreviewed; occurrence→claim links were machine-relinked. ← Back to the registry
S0124 · flesch_reading_ease_formula · registry identity

Flesch Reading Ease Formula

Flesch · 1948
study independent3 occurrences across 2 books · load 6

Resolution status: ambiguous

Every occurrence, grouped by book and chapter, with the claim it was linked to support and (where the extraction regenerated one) the underlying warrant.

1977 · The Philosophy of Composition
Rudolf Flesch's Reading Ease formula based on syllables per word and words per sentence.
direct Simple readability formulas based on word-length and sentence-length are empirically valid for predicting text difficulty.
ch 3 · statistical_data · poc:ch3_E17
Warrant (explicit): The most efficient way to measure a complex phenomenon is to identify the smallest number of easily quantifiable variables that correlate strongly with subjective difficulty.
could fail ifReadability formulas measure surface features but ignore the conceptual density and prior knowledge of the reader, which are the actual primary drivers of difficulty.
2023 · Shared Knowledge
Rudolf Flesch's original 'Reading Ease' formula from the 1940s.
direct Rudolf Flesch's original Reading Ease formula was designed for writers seeking to write best-sellers rather than for educators assessing reading level.
ch 7 · historical_example · sk:ch7_E4
Warrant (implicit): A tool designed to optimize commercial appeal for a general adult audience is inherently ill-suited for gauging the developmental progression of children's literacy.
could fail ifThe underlying linguistic metrics of readability, such as sentence length and syllable count, may be universal indicators of cognitive load that apply to both novice readers and adults seeking clarity.
The specific mathematical formula for Flesch Reading Ease involving sentence length and syllables.
related Rudolf Flesch's original Reading Ease formula was designed for writers seeking to write best-sellers rather than for educators assessing reading level.
ch 7 · statistical_data · sk:ch7_E5

As they appeared before normalization/consolidation into this source identity.

  • Flesch, 1940s