This paper describes a new method for investigating consumer preferences for product design, the Interactive Concept Test. In this test, respondents specify their own, preferred design by interactively adjusting the attribute levels of a randomly chosen product design. The Interactive Concept Test gives insight into the formation of consumer preferences for products, in addition to how preferences are structured. Furthermore, the test is an example of the application of multimedia technologies in consumer research. In this paper, it is shown how the method works. Furthermore, some results of an illustrative study are discussed.