Shifting ground: A definite deficit in adult article production

Shifting ground: A definite deficit in adult article production Lara Klainerman Hochstein (Larak@ling.ucsd.edu) Department of Linguistics, 9500 Gilman Drive San Diego, CA 92093-0108 USA David Barner (Barner@ucsd.edu) Department of Psychology, 9500 Gilman Drive San Diego, CA 92093-0109 USA Abstract they fail to appreciate the listener’s lack of knowledge about the large triangle. These findings have raised the possibility that perspective-taking in conversation may not be as automatic or effortless as previously assumed. Horton & Keysar (1996) proposed a two-step monitoring and adjustment model of audience design, in which speakers initially formulate their utterances without taking their interlocutor’s perspective into account and only later monitor and revise their output if they have sufficient time and processing resources. Pickering and Garrod (2004) and Keysar (2007) have even suggested that adults do not routinely take their interlocutors’ mental states into account when producing and comprehending speech: “People don’t rely on the beliefs and knowledge of their addressees to design what they say.Of course, sometimes they might. However, such consideration of the mental state of the other is not done systematically” (Keysar, 2007; 72). Under this view, adults are by default egocentric, yet they often appear to be taking their interlocutor’s mental states into account simply because speakers and interlocutors typically share the same knowledge and context. The evidence regarding adults’ conversational perspective-taking abilities remains inconclusive, however. The referential communication tasks which show perspective-taking failures in adults typically place subjects in somewhat unnatural communicative situations in which they are asked to uniquely identify a given object. Since the primary goal of the task is to be as informative as possible, and since subjects are made explicitly aware of this goal, they may resort to unnatural statements that would otherwise not occur in naturalistic speech. Furthermore, there is some evidence that adults do in fact show sensitivity to their interlocutor’s mental states when planning utterances. For instance, Brennan and Clark (1996) found that speakers who establish specific terms (e.g., “the high heel”) with a particular partner switch back to more basic- level terms (e.g., “the shoe”) when paired with a new partner – indicating awareness on the part of the speakers that their new partner lacks knowledge about the more specific term. Similarly, Heller et al. (2009) show that speakers tend to provide only the name of an object when their interlocutor is familiar with this name, yet provide additional descriptions when their interlocutors are not familiar with the object’s name, suggesting that they are Interlocutors are typically thought to keep track of information that is shared between speaker and listener (i.e., common ground) and information that is available only to the speaker (i.e., privileged ground). In this study, we investigated whether speakers take their interlocutor’s knowledge into account when choosing between definite articles (e.g., the) and indefinite articles (e.g., a) in the context of object reference. In Experiment 1, we found that a surprisingly high number of subjects inappropriately use the definite article to refer to objects in privileged ground, suggesting that considering interlocutors’ mental states during language production is effortful and does not always come naturally. In Experiments 2-6, we explored various factors that influence whether or not speakers accommodate the knowledge states of interlocutors. Keywords: common ground; perspective-taking; audience design; definiteness; indefiniteness Introduction Communication is often described as a cooperative act in which speakers and listeners work together to achieve mutual understanding. Speakers tailor the style and content of their utterances to the specific needs of their listeners – a process known as audience design – while listeners provide important feedback such as acknowledgement or requests for clarification (e.g., Clark & Brennan, 1991). Throughout this process, interlocutors are thought to keep track of information that is shared between speakers and listeners, known as common ground, and information that is available only to one party, known as privileged ground (e.g., Clark, A number of recent studies, however, have found that in simple referential communication tasks, adults often fail to take their interlocutor’s perspective into account and instead inappropriately mention privileged information (e.g., Horton & Keysar, 1996; Wardlow & Ferreira, 2003). In some of these studies, for instance, one subject (the speaker) can see two objects of the same type that differ only in size (e.g., a small triangle and a large triangle), while the other subject (the listener) can only see one of these two objects (e.g., the small triangle). Since only one triangle is visible to the listener, speakers should refer to the mutually visible object as simply “the triangle”. However, subjects frequently refer to this object as “the small triangle”, instead, suggesting that