Readability of Vocational Horticulture Instructional Materials. Summary of Research 31.

A study examined the readability of vocational horticulture instructional materials used by 40 schools participating in the 1981 Ohio Horticulture Achievement Testing Program. During the first part of the study, researchers administered a mail questionnaire to 31 teachers to identify the materials that were used most frequently, to obtain descriptive data about the teachers, and to collect teacher estimates of the readability of the materials being used. Next, the researchers utilized the Dale-Chall Readability Formula to estimate the readability of 75 instructional materials. The analysis revealed that difficult vocabulary constituted from 16 to 29 percent of the vocabulary included in the sample texts. As did previous researchers, the designers of this study found only a nonsignificant correlation between readability scores and frequency of use. Because of the very low degree of association found between the respondents' length of teaching experience and the readability of the instructional materials that they used, the researchers concluded that increased teacher experience does not increase instructors' ability to estimate readability. In general, teacher estimates of student ability matched their estimates of the readability of instructional materials. In most cases, however, teachers underestimated the reading difficulty of materials as it was determined according to the Dale-Chall formula. (MN)