Last Rites for Readability Formulas in Technical Communication

Abstract

Some reading researchers and technical communicators assume the efficacy of readability formulas. Reading researchers use such formulas to equalize the reading difficulty of texts used in experiments. Results of an informal Internet survey indicate that some professional writers and editors use readability formulas that are integrated into word-processing software. This article proposes that readability formulas fail to predict text difficulty. The results of an experiment demonstrate that “text difficulty” is a perception of the reader and therefore cannot be objectively calculated by counting syllables, word length, sentence length, and other text characteristics.