This study is designed to develop a checklist of teacher competencies (TECOMP I) based on an analysis of teaching tasks in keeping with a cybernetic model, to secure and analyze critical responses to the checklist items, to relate these judgments to the characteristics of the several items, and to clarify issues regarding the construction and utilization of competency lists. Contents of this study are divided into three sections. Section 1, "The Development and Character of the Checklist," provides background information, presents TECOMP I, describes a cybernetic model of the teaching-learning process, and lists uses of the checklist. Section 2, "The Application of TECOMP I to Prospective and Present Teachers," includes data obtained from teachers who were both graduate students and supervisors of undergraduate student teachers regarding the importance of the checklist items and their placement in training. Section 3, "Conclusions and Discussion," presents a summary of major findings and some implications of the study. Appendixes include the following items: (a) "The Teacher Competencies Checklist together with Decile Rating Indicators and the Categorical Classification of the Items," (b) "Lower and Upper Limits of Each Decile," (c) "Mean Item Values in Importance and Placement Ratings," and (d) "Major Training Emphasis Prior to, During, and After Student Teaching." (PD)