Four Introduction to Psychology and six Developmental Psychology graduate teaching assistants collected student ratings from their students with the newly created Evaluation of College Instructor (ECI) rating instrument. A total of 82 Introduction to Psychology students and 186 Developmental Psychology students completed the ECI shortly before the end of the Spring 2001 semester. The data for all Intro and all Developmental sections were combined, and then analyzed separately. Results revealed that a different set of research variables influenced student ratings in the two types of courses. Specifically, whether the class was challenging and whether the students were motivated by the instructor to perform well in the course, were the most (and the only) potent variables for the Introduction to Psychology students. Whether students were motivated by the instructor, and whether students struggled to understand the material influenced the ratings of the Developmental Psychology students. Most interestingly, when six different dimensions of teaching performance were regressed onto the ten research variables, the same predictors emerged as significant predictors of student ratings for those specific dimensions. An appendix contains the ECI rating scale. (Author)