Memory for sex of the speaker and language of presentation of a spoken message was high and reliably better when the features were instrumental for comprehending the message than when they were not. This suggests that the physical characteristics of an event may be deeply or elaborately encoded when they are meaningful in light of the task demands. Furthermore, memory about the acquisition event was superior when its physical characteristics matched those of the test probe (e.g., both were presented in a male voice) than when they mismatched. This facilitation was greater when the feature was meaningful than when it was non-meaningful. It was hypothesized that memory of an event could occur either by retrieving the episodic trace representing the particular event or by constructing the event from an abstract, thematic code that integrates several, conceptually related events. It is suggested that elaborate encoding--relating an event to a structure of other events--facilitates memory because it permits the use of thematic knowledge at the time of retrieval. (Author/PN)