The purpose of this study was to determine if making specific changes in teaching, changes that were validated by experts, would change the overall student ratings of instructors. Thirty graduate teaching assistants who participated in a workshop on improving lecturing skills significantly improved their scores on specific lecturing behaviors that were taught in the workshop when videotapes of their teaching were evaluated by experts. A group of 18 undergraduate students then assessed these same videotapes giving an overall rating of the instructor and a rating of the instructor's warmth. An analysis of the data generated the conclusion that improvement on the part of instructors in specific areas is not likely to affect their global ratings. Additionally, student perceptions of an instructor's warmth play a large part in determining the overall rating the students give the instructor, whereas, specific ratings do not seem to account for the overall global rating. The data appear to support the idea that, while specific skills can be changed through intervention, the overall impressions that students have of their instructors do not necessarily improve. (Author/PN)