State and school textbook committees, administrators and teachers, who are responsible for the selection of textbooks frequently make use of evaluation scales that involve consideration of the author's qualifications and the book's organization, content, presentation, accuracy, readability, adaptability, teaching aids, illustrations and appearance (14). Generally, those who have selected textbooks in science have not availed themselves of specific information concerning the reading difficulty of these materials. The rating supplied by the publisher is often given as an estimate which, if it is near the grade placement of the subject, satisfies the publisher's purpose. However, school people must heed the warnings from the various studies of Mallinson (8) in which he concludes that "the levels of reading difficulty of many textbooks in all areas of science are too advanced for the students for whom they are written." In view of this conclusion, it is vital that readability ratings become an integral phase of the textbook selection process. Consideration must also be given to the reading ability of the students for whom the textbook is intended. Textbook selection committees, administrators and teachers tend to consider only the grade placement of the subject when dealing with the reading difficulty of the material. The dangers of this course are only too apparent to the teacher using the textbook, as obviously all students are not functioning in reading at the grade level of the subject placement. The reading achievement of the students enrolled in the course would provide more realistic data for determining the needs that are to be met by a particular textbook. PURPOSE The purpose of this study was to determine the reading difficulty level or the readability level of selected general biology textbooks, and to determine the level of achievement in reading of students enrolled in high school biology classes.
PROCEDUREFive biology textbooks (1, 5, 7, 11 and 13) selected by a state textbook committee were analyzed by the Dale-Chall Formula for Predicting Readability (4). Three hundred and fifty-seven students en-689
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.