The present study was designed to investigate textbook development criteria for the evaluation of printed textbooks and e-books used in open and distance learning (ODL) with regard to several categories including content, language and expression, visual design, individual learning, and software. To this end, the study was conducted using a qualitative research method known as document analysis. A number of key words including "distance learning course materials", "open learning course materials", "textbook development criteria", and "individual learning principle in open learning" were used to search the online databases such as YOK TEZ (Turkish Higher Education Council Dissertation Database), Google Scholar, ERIC, and Web of Science both in Turkish and English languages. The analysis identified a total of 108 potential criteria and these criteria were then reduced to 70 criteria and divided into 5 categories by a group of three experts with relevant experience. These 5 categories included content, language and expression, visual design, individual learning, and software, of which the software category was evaluated for e-books alone. The results indicated that the categories including visual design and language and expression were the most commonly emphasized criteria, and individual learning, feedback, and e-book were the most commonly investigated topics. Accordingly, it was revealed that although there is a large body of literature investigating textbook development, there is paucity in the literature regarding textbook development criteria in ODL.
