The purpose of this study was to compare traditional classification training for a set of abstract concepts with multiple-relations training consisting of inference practice and the use of a content diagram. To examine this, 200 undergraduate and graduate psychology students completed a Web-based tutorial covering the abstract concepts of a psychological theory of language and cognition. All participants received the same core instructional content and practice activities varied by experimental condition: some participants received classification training, some received multiple-relations training, some received a combination of both, and some received neither. Performance on a posttest with three subsections was evaluated. Participants who received classification training were significantly better at identifying new instances of the concepts than participants who did not. Neither classification training nor multiple-relations training had a significant effect on ability to identify concept definitions or answer application questions. Implications for the development of instruction for abstract concepts are discussed. (Contains 4 tables and 1 figure.)