Information Used in Text Comprehension (page 4)

If readers are to make sense of texts, they must develop mental models of the texts (Sanford & Garrod, 1998). In addition to comprehending novel words and complex syntax, they must use three kinds of information: content facts, content schemata, and text grammars (Kieras, 1985). Content facts are the simple propositions that are conveyed by the texts (e.g., facts about ants or facts about a character in a story). At this level, information does not have any superordinate organizational content. If students recognize the vocabulary words used to present the facts, they can comprehend the individual pieces of information. To gain meaning from the overall text, however, a student must have a content schema, or be able to organize a content schema from the facts presented in the text. A content schema represents a superordinate organization of a mass of possible content facts. For example, one can have a content schema for the social structure of ant or bee colonies, the metamorphosis process of caterpillars and tadpoles, or the activities at a birthday party. The speed of reading and comprehension of a text becomes easier when the reader possesses intuitive knowledge of the text grammar structure of a text (Kieras, 1985). A text grammar or macrostructure is a schema that represents a frequent organizational pattern of textual elements that is independent of specific content.

The role of schemata in text comprehension has been extensively studied (Anderson, 1994; Bartlett, 1932; Bransford, 1994; Kintsch, 1998; Rumelhart, 1980; Stein & Glenn, 1979; Van Dijk & Kintsch, 1983). Schemata are hierarchically organized sets of facts or information describing generalized knowledge about a text, an event, a scene, an object, or classes of objects (Mandler, 1984). (Note: Some authors use the term script to refer to an event schema—the stereotypical knowledge structures for common routines such as going to a restaurant, taking a subway, or going to a party [Beaugrande, 1980; Bower, Black, & Turner, 1979; Nelson, 1985; Schank & Abelson, 1977]. A script can be viewed as a specific type of schema.) Our schema knowledge enables us to behave appropriately in familiar situations, and when our schema information is applied to discourse (oral or written), it enables us to make the inferences necessary to comprehend the text—it enables us to read between the lines. If you have an elaborated schema or script for restaurants and you read the sentences, "John was hungry. He looked in the yellow pages," you would know that John may be intending to call a restaurant for reservations or to order a pizza—you would also know that he is not intending to eat the yellow pages. The ability to draw inferences is essential for critical and dynamic literacy. Although children who are poor comprehenders (despite adequate decoding skills) are less able than good readers to answer all types of questions about texts, they exhibit particular difficulty answering questions that require them to draw inferences (Oakhill & Yuill, 1996). In fact, when both good and poor comprehenders were able to refer to the text to answer questions, there was no difference between the good and poor comprehenders on literal questions. The availability of the text made little difference in the poor comprehenders' ability to answer the inferential questions. This deficit in inferencing may be related to lack of relevant schema knowledge, to difficulty in accessing relevant schema knowledge and integrating it with the text because of processing limitations, or to their being unaware that inferences are necessary.

Readers' schemata affect both learning and remembering of information in a text. Schemata have a variety of functions in relation to texts (Anderson, 1994):

• A schema provides a scaffold for assimilating text information. Schemata provide slots for information. For example, there is a slot for a weapon in a murder mystery and a slot for a horse in a Western. Information that fits the slots is easily learned.
• A schema facilitates selective allocation of attention. Having a schema enables readers to know what is important in a text and to devote attention to that which is most important.
• A schema enables inferences. No text is completely explicit. Readers must read between the lines. This is particularly necessary when interpreting character emotions and intentions. Consider, for example, the story Alice Nizzy Nazzy: The Witch of Santa Fe (Johnson, 1995). The witch is preparing a stew to keep herself young. She has put Manuela, a young child who has wandered into her home, into the cooking pot. The witch cannot find the petals from the black cactus flower to add to the pot. "Suddenly she (Manuela) shouted out, 'I know where the black flower is!' " If students have a schema for witches, children, and cooking, they can predict that Manuela intends to trick the witch.
• A schema allows orderly searches of memory. Readers need not memorize the details of a story. For example, if the story is about a camping trip in Yellowstone Park, the reader need not focus on backpacks, tents, and sleeping bags. If the character encounters a dangerous animal, the search for the animal name is reduced—it won't be a rhinoceros or a polar bear.
• A schema facilitates editing and summarizing. Because schemata contain the criteria for importance, they are used to retrieve the information needed for a summary and to exclude irrelevant or insignificant information.
• A schema facilitates comprehension monitoring. If readers have schemas for the text content, they are more likely to recognize anomalous information in a text or attend to information that adds to or contradicts their present schema knowledge.
• A schema permits reconstruction. When readers cannot remember some components of a text, they can use what schema knowledge they have, along with the specific text information they can recall, to hypothesize about the missing information.