Overspecification in written instruction

A much debated question with respect to referential expressions is under what conditions speakers and writers produce overspecified expressions, i.e. expressions that contain more information than what is necessary for unique identification. In an earlier study we found that overspecifications facilitate the identification process for the understander, in particular if they contain complete object information and/or complete location information. In the present study, a production experiment is discussed in which the importance (high, low) of the instructed referential task was manipulated. In the high-importance condition more overspecifications were produced than in the low-importance condition, and this was particularly the case for overspecifications that facilitate identification for the understander.