The aim of utterance interpretation is to integrate what is being said with what has been said so far. This paper examines some factors which affect the "on-line" construction of a coherent discourse representation. Building on ideas presented in Garrod and Sanford (1977) and others we report a series of studies showing that the time taken to assign an antecedent to a gerund can be influenced by semantic featural overlap between material in the prior discourse and the New/incoming material. Whether the effect is facilitatory or inhibitory depends on the item's role in the discourse representation. The data distinguish between two types of response to semantic overlap between the immediate input and the semantic properties of the discourse representation. The first is a reflexive allocation of processing resources to discourse entity linked to semantic overlap information. The second is a facilitatory effect on the evaluation processes which determine the appropriate antecedent. When the prior discourse contains a word (e.g., jogging) denoting a conceptual property which is semantically similar to the immediate speech signal (e.g., Running towards ... ), antecedent assignment is facilitated but only when the property is linked to the pragmatically likely subject of the gerund. Antecedent assignment times are slowed when the conceptual property is linked to the less pragmatically likely subject of the gerund. We suggest that a processing conflict occurs when there is a mismatch between the semantic structure and the focus structure of the discourse representation