The purpose of this paper is to review progress in the development of an instrument by which to study the dimension of teacher-student relationships that can be related to power, and by which to study the contribution of this dimension to the learning climate. Sections of the paper are: Theoretical Basis for an Instrument; Development of an Instrument; Testing the Instrument; Examination of Individual Statements; Next Steps in Instrument Development; and Use of the Instrument. The value of the instrument will be to test hypothesis based on a notion that the expectations of the teacher that the student brings to the learning situation and the quality of the relationship that develops between student and teacher during the learning situation may be the most critical factors in successful implementation of designs. Appendix A provides the Instrument to Differentiate Students' Perceptions of Teachers' Bases of Power; Appendix B is a Master List of Items; and Appendix C is Perceptions Differentiations. A brief list of references is provided. (DB)