Readability Formulas

Flesch Reading Ease and Flesch–Kincaid Grade use sentence length and syllable counts. They do not establish whether a reader understands a game, an undefined term or a chain of reasoning.

Reading Ease = 206.835 − 1.015 × words/sentences − 84.6 × syllables/words
Grade = 0.39 × words/sentences + 11.8 × syllables/words − 15.59

A higher score is not a substitute for a reader explaining the proposed experience in ordinary language. Different text extraction and syllable-counting methods can also change results; compare like measurements and state uncertainty.

Sources

• Flesch–Kincaid readability tests: formula definitions.
• Bailin and Grafstein, The linguistic assumptions underlying readability formulae: a critique (2001) and ERIC record: limitations of assessing reading difficulty through formulas.

The former project-specific measurements and withdrawn comparisons are not retained as evidence for the restart.