On standard views of sentence processing, meaning construction results largely from parsing. A string is decomposed into representations of syntactic or structural information, and of lexical semantics, or word meanings. The meaning construction system on such a view consists of two discrete components, one devoted to word meaning and one devoted to syntactic structure. Parsing is accomplished by combining these two sorts of information to assemble a context-invariant meaning. On such approaches, pragmatics is knowledge that enables speakers to adapt context-invariant meanings to the situation at hand. In contrast, Part I outlines a constructivist comprehension system in which contextual and background knowledge do more than merely clarify the application of context-invariant meanings. Rather, meaning emerges from the integration of linguistic and nonlinguistic knowledge, as meaning and background are intimately intertwined.

However, the interdependence of meaning and background presents the language user with a profound challenge. She must determine which background assumptions are relevant at a given time, and which should be ignored. In fact, the challenge becomes quite poignant when we realize that background assumptions differ from context to context, and can even conflict. For example, note the following exchange between an interviewer and a famous Shakespearean actor.