The purpose of this study was to develop and pilot modular materials about the reading instructional process to be used in the inservice training of principals. The first step in designing modules for elementary principals involved identifying three major categories of skills Three modules were designed under the headings of the major categories identified. A 75-item pretest was constructed for purposes of evaluating the students' prior knowledge of each of the three areas. The materials were field-tested with 36 principals involved in a program of inservice training in the area of reading. Eighteen participants reached mastery level (80 percent correct) and 13 scored below mastery level on the first module. Eight principals reached mastery level and 18 scored below mastery level on the second module. Eleven of the participants reached mastery level on the third module. The materials developed in this study appear to be effective in helping principals gain competencies in the reading instruction area. (Recommendations based on the study are included.) (Author/RB)