By 4 years of age, children have been reinforced repeatedly for searching where they see someone point. In two studies, we asked whether this history of reinforcement could interfere with young children's ability to discriminate between a knowledgeable and an ignorant informant. Children watched as one informant hid a sticker while another turned around, and then both informants indicated where they though the sticker was, either by pointing or by using a less practiced means of reference. Children failed to discriminate between the two informants when they pointed, but they chose the location indicated by the knowledgeable informant when the informants used a cue other than pointing. Pointing can disrupt as basic an understanding as the link between seeing and knowing. (Contains 1 table and 1 figure.)