The field of instructional design has traditionally treated concepts as discrete learning outcomes. Theoretically, learning concepts requires correctly isolating and applying attributes of specific objects into their correct categories. Similarity views of concept learning are unable to account for all of the rules governing concept formation, patterns of concepts, and concepts-in-use. Probabilistic-prototype and exemplar views have accommodated some of the inherent fuzziness of concepts. Concepts can only be fully understood as processes of conceptual change, the reorganization of conceptual frameworks. Although very little research has focused on assessing conceptual change, the theories of conceptual change recommend assessing patterns of concepts and concepts-in-use. Descriptions of pertinent assessment methods are presented. (Contains 3 figures.)