The present study examined the role of hedges in a referential communication task. Pairs of participants received an identical set of cards, each card displaying a geometric configuration (a "tangram"). One participant, the director, instructed their partner, the matcher, to reproduce a series of predetermined tangram sequences using their own cards. Directors sometimes included a hedge in their description of a tangram (e.g., "looks 'kinda' like an eagle"), and more so the first time than on subsequent mentions. The present study tested the hypothesis that, by revealing their uncertainty regarding the adequacy of their description in conveying the intended meaning, directors signal a possible difficulty in establishing reference. This in turn prompts their addressee to display, rather than merely assert, their understanding (by presenting a description for the tangram the matcher believes the director is referring to, for the director to evaluate). Analyses of matchers' responses to descriptions that directors had hedged or not confirmed the hypothesis. This finding supports the view that conversational partners work together to reach the mutual belief that they have coordinated what the speaker means and what their addressee takes them to mean. Conversational partners expend more joint effort when they deem the risk of misunderstanding to be high than when it is perceived to be low.