AGRICOLA CAT 90939434; Contains Abstract and Table of Contents only, Blacksburg, VA : Virginia Polytechnic Institute and State University, 1990. vii, 113 leaves : ill., forms (Ph. D. dissertation; Educational Research and Evaluation), This study investigated a systematic process for improving the understanding or comprehensibility of the educational publications produced by the Cooperative Extension Service. A model of a publication development process based on learning principles was created. This study investigated the effectiveness of the model with Extension subject-matter specialists developing publications for 4-H youth. Specifically, this study was conducted in three parts: the model of the text-development process was taught to subject-matter specialists; the specialists in turn used the model to develop educational texts for 4-H youth; and finally comprehensibility testing of the text passages produced by the specialists with 4-H youth members and adult leaders was conducted. This study confirmed that the utilization of learning principles within the text-development process can improve the comprehensibility of subject matter information presented in Extension educational publications. (original)