The present study investigated the interaction between college student entry characteristics and effective instruction. The experimental design involved 380 introductory psychology students and consisted of a Lecture Organization (low, high) by Test Anxiety (low, moderate, high) 2 x 3 design. The dependent variables included student attention, achievement, cognition, affect, and motivation observed during a lecture presentation. A set of hypotheses dealt with identifying which types of students, and under what teaching conditions, learning was enhanced or thwarted. First, test anxiety yielded differences in student learning outcomes. Second, analyses of Test Anxiety with Lecture Organization yielded relatively consistent patterns across a number of learning outcomes: lecture attention, student achievement, perceptions of control, affect, and motivation. High text-anxious students were unable to benefit directly from high-organized instruction though organized instruction did increase these students' motivation to attend future classes. Specific explanations are postulated on how the differences in effective teaching behaviors and student differences may operate together to produce ideal and less than ideal learning environments. Finally, a number of new directions are provided for future research and suggestions are made for classroom instructors and college students. (Contains 82 references.) (Author)