Readability formulas in the new millennium
Karen A. Schriver · ACM Journal of Computer Documentation · 2000
While readability formulas were intended as a quick benchmark for indexing readabilty, they are inherently unreliable: they depend on criterion (calibration) passages too short to reflect cohesiveness, too varied to support between-formula comparisons, and too text-oriented to account for the effects of lists, enumerated sequences,and tables on text comprehension. But readability formulas did spark decades of research on what comprehension really involoves.