This investigation employed discriminant analysis to improve the usefulness of student-faculty ratings in detecting differences in lecturer types. Equivalent groups of college students viewed lectures delivered by a Hollywood actor so as to vary in number of substantive teaching points covered (high, low) and presentation manner (enthusiastic, unenthusiastic). Students rated lecturer effectiveness using an 18-item questionnaire like those commonly used. Optimal scoring methods were derived in the first study for the purpose of differentiating among lecturer types and were cross-validated in a second study of groups of students who saw and rated the same lectures. Scoring methods derived in the first study were valid in relation to differences in faculty enthusiasm in both studies but were not valid in the second study for differences in information-giving. Results were explained in terms of the “Doctor Fox Effect” and suggestions were offered for future research.