In referring to a target referent, speakers need to choose a set of properties that jointly distinguish it from its distractors. Current computational models view this as a search process in which the decision to include a property requires checking how many distractors it excludes. Thus, these models predict that identifying descriptions should take longer to produce the larger the distractor set is, independent of how many properties are required to identify a target. Since every property that is selected is checked, they also predict that distinguishing a target should take longer the more properties are required to distinguish it. This paper tests this prediction empirically, contrasting it with two alternative predictions based on models of visual search. Our results provide support for the predictions of computational models, suggesting a crucial difference between the mechanisms underlying reference production and object identification.