During dialog, references are presented, accepted, and potentially reused. Two experiments were conducted to examine reuse in a naturalistic setting. In Experiment 1, where the participants interacted face to face, self-presented references and references accepted through verbatim repetition were reused more. Such biases persisted after the end of the interaction. In Experiment 2, where the participants interacted over the phone, reference reuse mainly depended on whether the participant could see the landmarks being referred to, although this bias seemed to be (...) only transient. Consistent with the memory-based approach to dialog, these results shed light on how differences in accessibility in memory affect the unfolding of the interaction. (shrink)