Preschooler awareness of listener informational need in relation to linguistic reference.

Making appropriately informative requests necessitates understanding what others know and what they are paying attention to. Matthews, Butcher, Lieven and Tomasello (2012) carried out two training studies in which 21?2-year-olds requested one of an array of pictures. If the child was ambiguous (e.g. 'pig one!' when the array contained two pigs), E2 provided feedback (e.g. 'Which pig?'). They found that 21?2-year-olds cannot take elements of picture detail into account when determining listener informational need. However, their pictures frequently required the children to infer actions and to produce reduced relative clauses (e.g. 'Can I have the pig dancing'). We modified Matthews et al.'s (2012) procedure to reduce cognitive load, primarily by reducing array size and modifying the stimuli so they contained no actions so 21?2-year-olds could produce complex requests by using early- acquired prepositions (e.g. 'rabbit on boat'). In each training trial, children requested one of two 'similar' pictures which contained identical animals (e.g. TARGET: pig on bike, DISTRACTOR: pig with cake) and received feedback if their first request was ambiguous. There were two post-test conditions: 'similar' vs. 'dissimilar' distractors. Our 21?2-year-olds were significantly less likely to produce complex referring expressions for 'dissimilar' pictures, showing sensitivity to when disambiguating information was needed. There was a relationship between individual differences in parent-rated conversation skills and training outcome. We discuss our data in terms of the roles of cognitive load reduction alongside how discourse around repair can focus attention on the need to incorporate listener informational need when planning requests.