A typology for the classification of products according to their comparability is presented and hypotheses about the levels of comparison used by consumers in making choices among durable goods are proposed. The hypotheses are tested with data provided by subjects who made choices among durable goods and indicated their choice criteria in an interactive survey. Subjects tended to use abstract levels of comparison even when items could be compared easily on concrete attributes, and choices between more comparable items were more difficult to make than those between less comparable items.