Using a specially-constructed category system (CATS), biology lessons are analyzed for attribute-treatment interaction (ATI) and the data submitted to analysis. Relationships between fifteen individual predictors (general ability, four personality factors, two cognitive preferences, treatment, and seven first-order attribute-treatment interactions) and criterion variables (four attitude scales and two achievement tests) are studied using multiple regression analysis. The unique contribution of each term, controlling for all others, is tested. Among the results reported, "enjoyment in biology" is considered to be a function of a cautious, convergent outlook, and an intellectual disposition. General ability and an intellectual disposition lead to high scores on a memory task in biology, and on this criterion, class-centered teaching is considered better for students who are both open-minded and have a cognitive preference for rate learning, and individual-centered teaching is considered better for dogmatic students and those with a cognitive preference for principles. On an achievement test sampling higher cognitive processes, high general ability, open-mindedness, and a cautious personality are advantageous and individual-centered teaching is better than class-centered teaching for all but students with a highly intellectual disposition. (Author/MA)