Students often fail to store new information in memory in a way that is accessible or useful. The information they have acquired is inert. This paper examines the inert knowledge problem in the context of learning from informational expository text. Kintsch and van Dijk (1978) have suggested a framework for understanding learning from expository text which first describes the textbase, a representation of the semantic content and organization of the text. A second aspect is the situation model, closely tied to the textbase, which represents the reader's understanding of the situation being described by the text. Reading and constructing only the textbase may leave the learner with inert knowledge. Understanding situation models and how to construct them may facilitate learning from text and is a promising direction for research. (Contains 154 references.) (SLD)