The goal of writing is to communicate, and the goal of reading is to understand. To fully understand reading comprehension would be to understand most of the fundamental problems in cognition. The challenge is daunting. A starting point for studies of reading comprehension is to assume that reading comprehension will involve many of the same processes as comprehending speech. How do we begin to grapple with how the mind represents the meanings conveyed by language, whether written or spoken?
Kintsch and Rawson lay out a highly influential theory of comprehension. The theory sees comprehension as depending upon largely automatic processes somewhat akin to the processes subserving perception. Two major levels of representation are distinguished: a textbase representation that represents the linguistic structure of the text and its meaning, and a situation model (a mental model of the situation described by the text). The textbase representation will have a number of different levels of representation, including microlevel representations (word and proposition level representations, for example) and a macrolevel representation of how ideas in a given passage relate to each other. If this were not complicated enough, for a full understanding, the textbase representation must be related to the situation model, a more abstract representation that is not exclusively verbal and includes a wide range of world knowledge that may include imagery and emotional content.
Perfetti, Landi, and Oakhill move on to consider how reading comprehension skill develops. They point to the likely critical importance of the child's ability to identify words fluently and retrieve their meanings (cf. Gough & Tunmer, 1986). In terms of Kintsch and Rawson's model, processes in accurately constructing a textbase representation are critical, and one potential set of limiting factors concerns word identification and access to adequate vocabulary knowledge. Constructing a situation model, however, will require inferences to be made and Perfetti et al. critically discuss many studies that have attempted to link inferential skills to the development of reading comprehension skill, as well as the development of comprehension monitoring strategies and syntactic skills.