A general model is described that views similarity judgment as a contrasting of product features. The relative influence of common and distinctive features on perceived similarity is considered a function of the context or task environment. A memory probe is used to measure the common and distinctive features consumers associate with various products. The feature measures are then used to estimate the model under three different task environments: similarity, dissimilarity, and subject/referent similarity. The results support the model and the effect of the task environment on judgments of interproduct similarity.