In a calculation that considers the number of syllables per word and the number of words per sentence, the Flesch formula produces a score that can be aligned with reading difficulty.
Flesch Formula = (11.8 * syllables per word) + (0.39 * words per sentence) - 15.59, rates text on U.S.
4, at 151-52, 165-69 (questioning the validity of Microsoft's version of the Flesch Reading Ease formula, and explaining the perils of using the Flesch formula beyond its intended parameters).
(33) A particularly insightful criticism of computerized readability formulas in this regard was raised by Professor Sirico, (34) who claims that the Flesch formulas used by Microsoft Word (which are the formulas we used in our research) do not actually use the Flesch formulation at all, but seem to rely instead on "some algorithm to approximate the number of syllables." (35) This is why there may be discrepancies between various versions of the Flesch formulations, as well as differences between computer calculations and hand calculations of the same formula.
The Spanish label comes from the name of the scientist who adjusted the initial Flesch formula
Despite of its age, the Flesch formula
is still widely used.
(9.) The Flesch formula
is: Reading Ease = 206.835 - 0.846wl - 1.015sl, where wl equals the number of syllables per 100 words and si equals average sentence length.
The Flesch formula
and other similar formulas rely chiefly on average sentence length and average number of syllables per word to estimate difficulty.
Interest levels as measured by the Flesch formula
are generally at the `interesting' or `mildly interesting' level though Science texts appear to rate `dull' at two age levels.
We chose the Flesch formulas
because we wanted to see if using longer sentences and longer words correlated with success on appeal.