33 boys in Grades 9 and 10 were formed into 3 groups and learned materials in 1 of 3 ways: by rule and example, by guided discovery, and by the S's own discovery. Best performance was found with guided discovery, worst for rule and example, and intermediate for self-discovery. Discussion emphasizes "what is learned" by each method rather than the importance of "how it is learned." (PsycINFO Database Record (c) 2006 APA, all rights reserved)