The readability of textual materials in biology

Abstract

The study was primarily concerned with the readability of textual material used by fourth form, "0" level ability pupils. The techniques used to measure readability can be divided into two:- First, traditional measures (Fry's Graph, cloze procedure, subjective judgement) and second, methods of determining readability based on a psychological model of comprehension. The traditional measures were applied to two texts from a textbook by D.G. Mackean and to two versions of the same texts which had been rewritten so as to modify the language in the direction of increased readability. It was concluded that the two modified texts were easier to read with understanding. However, the measures did not agree as to the level of difficulty of each passage and reasons for this are discussed.The three traditional measures were critically evaluated and it was concluded that their reliability and even their validity is open to question; a major criticism being their limited consideration of psychological theory. The goal of the final part of this study was to match a rank order of difficulty for the four texts based on evidence from the traditional measures, with rank orders of difficulty produced by measures based on a psychological model of comprehension. Features of the text (number of propositions per 100 words, number of arguments per proposition) did not predict the expected rank order and further research is required to identify other determinants of reading difficulty. However, an index of reading time and recall successfully predicted the expected rank order, It was concluded that in biology, where the language of a text is not the only important determinant of reading difficulty, this index should be adopted as a new measure of readability.