Discourse

CLASSROOM DISCOURSE
Graham Nuthall

COGNITIVE PERSPECTIVE
Arthur Graesser
Natalie Person

CLASSROOM DISCOURSE

The term classroom discourse refers to the language that teachers and students use to communicate with each other in the classroom. Talking, or conversation, is the medium through which most teaching takes place, so the study of classroom discourse is the study of the process of face-to-face classroom teaching.

The earliest systematic study of classroom discourse was reported in 1910 and used stenographers to make a continuous record of teacher and student talk in high school classrooms. The first use of audiotape recorders in classrooms was reported in the 1930s, and during the 1960s there was a rapid growth in the number of studies based on analysis of transcripts of classroom discourse. In 1973, Barak Rosenshine and Norma Furst described seventy-six different published systems for analysing classroom discourse.

It soon became clear from these early studies that the verbal interaction between teachers and students had an underlying structure that was much the same in all classrooms, and at all grade levels, in English-speaking countries. Essentially, a teacher asks a question, one or two students answer, the teacher comments on the students' answers (sometimes summarizing what has been said), and then asks a further question. This cyclic pattern repeats itself, with interesting variations, throughout the course of a lesson.

The following excerpt from a whole-class discussion in a fifth-grade science class illustrates the nature of this typical participation structure. The teacher was reviewing what the students learned earlier in the day during a science activity on light.

Teacher. What's transparent? Something is transparent. What does that mean? We did that this morning, didn't we? What does transparent mean?

Valerie. Ah, it doesn't … It goes through.

Teacher. Can you explain that a little more? What goes through?

Valerie. Well it goes through like, um … You can, like, you shine a torch on and you can see.

Teacher. What goes through?

Valerie. The light.

Teacher. The light. Light can pass through something if it's transparent. What's the next one? Translucent. What does it mean? Jordan?

Jordan. Um, just some light can get through.

Teacher. Absolutely. Some light can get through. Can you look around the room and see an example of something that might be translucent? Well, you all can tell me something in here that's translucent because you discovered something this morning that would let some light through. What was it?

Clarice. Paper.

Teacher. Right. Some paper is translucent. It will allow some light to pass through it. Think of something else that's translucent.

Morgan. Oh, um, the curtains over there, you can see right through them.

Teacher. OK. Yes that's interesting. They do let some light through don't they. Another example? Think about light bulbs. Do you think some light bulbs would be translucent?

Pupils. Yes.

Teacher. They would allow some light through?

Pupil. No. Transparent.

Teacher. You think they're transparent. They let all the light through. I'm not too sure about that one either. So we might investigate that one.

This excerpt contains two episodes, each initiated by a question ("What does transparent mean?" and "Translucent. What does it mean?"). Within each episode the teacher directed the discussion by commenting on student answers and asking further questions. Each question set off a question-answer-comment cycle. At the beginning of the first episode, the teacher set the context by repeating the question several times and reminding the students that they had learned the answer during the morning's activity. This focused the students' attention and let them know (from their previous experiences with this teacher) that they were expected to know the answer.

The first answer (from Valerie) was not in the appropriate language of a definition. Through two further questions the teacher elicited the missing information and, through a summary, modelled the form of a scientific definition ("Light can pass through something if it's transparent.").

In the next episode, after Jordon copied this model to define translucent, the teacher asked a question to find out if the students understood the term well enough to identify an example ("Can you look around the room and see an example?"). After two answers (paper, curtains) the teacher provided additional help by suggesting an example (light bulb) and asking if the students agreed.

This excerpt illustrates how teachers use questions and student answers to progressively create the curriculum, to engage the students' minds, and to evaluate what the students know and can do. Underlying this exchange are the implicit rules and expectations that determine what, and how, teachers and students communicate. Each statement depends for its meaning on the context in which it occurs and, in turn, adds to the context that determines the meaning of subsequent statements.

Analysis of the patterns of interaction characteristic of most classrooms has shown that, on average, teachers talk for more than two-thirds of the time, a few students contribute most of the answers, boys talk more than girls, and those sitting in the front and center of the class are more likely to contribute than those sitting at the back and sides. Bracha Alpert has identified three different patterns of classroom discourse: (1) silent (the teacher talks almost all the time and asks only an occasional question),(2) controlled (as in the excerpt above), and (3) active (the teacher facilitates while the students talk primarily to each other). Recent attempts to reform teaching based on constructivist views of learning have called for teachers to ask fewer questions and for students to learn to state and justify their beliefs and argue constructively about reasons and evidence.

Earlier research on classroom discourse tended to focus on specific teacher or student behaviors, and, because of the key role that they play, teacher questions have been most frequently studied. Questions that challenge students to think deeply about the curriculum are more likely to develop students' knowledge and intellectual skills than questions that require recall of facts. In the excerpt above, the first question required simple recall ("what does transparent mean?) while the last question ("do you think some light bulbs would be transparent?") required the students to apply their understanding of transparent to their own experience.

The results of this early research were often equivocal, and researchers have argued more recently that specific utterances cannot be separated from the context in which they occur. Greater attention is now being paid to the ways in which meanings evolve as teachers and students mutually construct the unique discourse (with its roles, rules, and expectations) that characterizes each classroom.

An entirely different form of classroom discourse occurs when students are working together in small groups. The following excerpt is from a sixth-grade class studying Antarctica. The teacher organized the students to work in groups of two or three and instructed the students to "write down all the different types of jobs that you think people might do down in Antarctica." Ben, Paul, and Jim worked together, and Ben wrote down the list that they created. A nearby group consisted of Tilly, Koa, and Nell.

Ben. Most of the people there are scientists. In fact, just about all of them are.

Jim. Even the cooks would be scientists?

Ben. Not necessarily. OK.

Jim. Some of them?

Ben. Pilots.

Jim. Yeah, they'd need pilots.

Ben. All the things that need to be done to keep you living. You know, you need to have food, you need to have shelter.

Jim. I know, a driver. But you could have a scientist to be a driver.

Ben. What else would they do? A-ah, what are they called? I don't know.

Jim. Maintenance man. Maintenance man.

Tilly (overhearing). Thank you. Maintenance person!

Jim. Or lady. Maintenance person.

Paul. I'll tell you what. Um, explorer.

Jim. Um, expedition leader.

Ben (aware that the next group is listening). Just whisper, will you?

(to next group) Stop copying, you lot. Can't you use your own brain?

Jim. Yeah, they haven't got any brain to use.

Ben. Exactly.

Tilly. How many have you got [on your list]?

Jim. Twenty-eight thousand.

Ben. You'll have a job to beat that.

Jim (whispering to Ben). Mm. Builder?

Ben (to teacher passing group). They're copying.

Tilly and Nell. We are not.

Jim. Yeah, they are too.

Teacher. Oh, you don't need that sort of carry on.

Jim. Let's see, um … um … a guide.

Ben. Isn't that kind of like a leader?

Jim. No, 'cause the expedition leader is a leader. He just, the guide knows where everything is. The expedition leader doesn't.

Ben. An expedition leader has to know where everything is as well, or else he wouldn't be an expedition leader 'cause he's supposed to guide them all around the place and tell 'em where to go. He's the most experienced and therefore he should be the guide.

Jim. Yeah, but first of all they'd need a guide that's been there. While he's learning.

Ben. Well, he wouldn't be the leader while he was learning.

Jim. Yeah.

Unlike the teacher-led discussions, the structure of this excerpt is determined by the social relationships between the students. Paul and Jim thought Ben knew a lot and encouraged him to assume a leadership role. Mimicking the role of a teacher, he evaluated Jim's contributions ("Not necessarily. OK."), and provided guidance about how to think about the problem ("All the things that need to be done to keep you living."). When Jim suggested "guide," Ben questioned whether this was different from "expedition leader." Jim tried to defend his suggestion but, in the face of Ben's reasons and authority, he agreed with Ben. Researchers have noted that students are more likely to have their thinking changed by their peers than by their teacher, and that resolving differences is simultaneously about negotiating social relationships and consideration of reasons and evidence.

In this classroom there was an underlying competitiveness, and the teacher had previously talked with the students about the gender bias in their texts and personal experiences. These two agendas combined in the conflict that erupted between Ben's and Tilly's groups. When Tilly overheard Jim use a sexist title ("maintenance man"), she corrected him. This alerted Ben to the possibility that Tilly's group was listening and copying his group's ideas. He told his own group to whisper and told the other group they had no brains. Jim followed Ben's lead ("Yeah, they haven't got any brain to use") and challenged Tilly's group by claiming they had a list of "twenty-eight thousand" items. Clearly, the structure and function of this discourse reflects both the requirements of the task and the evolving social relationships and culture (e.g., about gender and ability differences) of this class.

Classroom Discourse and Learning

There have been two distinct approaches to explaining how classroom discourse relates to what students learn. Since the 1960s a large number of studies have been carried out in which frequencies of teacher and student verbal behaviors and interaction patterns (such as asking higher-order questions, providing structuring information, praising student answers) have been correlated with student achievement. These developed into experimental studies in which teachers were scripted to talk in specific predetermined ways. Such studies came to be criticized for their impersonal empiricism and lack of theory. They failed to consider the contextual nature of classroom discourse, particularly the meanings that participants attributed to what was being said.

As interest in the constructivist nature of language developed, researchers argued that the learning process was contained in the process of participating in classroom discourse. As students engage in the discourse they acquire ways of talking and thinking that characterize a particular curriculum area. For example, to learn science is to become an increasingly expert participant in classroom discourse about the procedures, concepts, and use of evidence and argument that constitutes science. This approach is supported by the theories of the Russian psychologist Lev Vygotsky who argued that the higher mental processes are acquired through the internalization of the structures of social discourse. There is still a need, however, for these detailed linguistic and ethnographic analyses of classroom discourse to include independent evidence of how students' knowledge and beliefs are changed by their participation in the discourse.

The field of discourse processing investigates the structures, patterns, mental representations, and processes that underlie written and spoken discourse. It is a multidisciplinary field that includes psychology, rhetoric, sociolinguistics, conversation analysis, education, sociology, anthropology, computational linguistics, and computer science.

Researchers in discourse processing have identified a number of mechanisms that promote learning. The practical mission of the field is to improve the comprehension and production of discourse in textbooks, tutoring sessions, classrooms, computer-based training, and other learning environments. While focused primarily on cognitive mechanisms, it is clear that cognitive, social, emotional, and cultural foundations are tightly intertwined in contemporary theories of discourse processing.

Levels of Discourse Processing

Discourse researchers have identified five levels of cognitive representation that are constructed during comprehension. These include the surface code, the textbase, the situation model, pragmatic communication, and the discourse genre. In order to illustrate these five levels, suppose that a high school student had a broken door lock and was reading the following excerpt from the book The Way Things Work:

Inserting the key raises the pins and frees the cylinder. When the key is turned, the cylinder rotates, making the cam draw back the bolt against the spring. (Macaulay, p.17)

The surface code is a record of the exact wording and syntax of the sentences. This code is preserved in memory for only a few seconds when technical text is read. The textbase contains explicit propositions in the text in a stripped-down form that captures the semantic meaning but loses details of the surface code. For example, the textbase of the first part of the second sentence includes the following: (1) someone turns a key, and (2) the cylinder rotates when the key is turned. The textbase is preserved in memory for several minutes or longer.

The situation model (sometimes called the mental model) is the referential mental world of what the text is about. In the above example, the situation model contains causal chains of events that unfold as the key unlocks the door, a visual spatial image of the parts of the lock, and the goals of the person who uses the lock. The construction of an adequate situation model requires a sufficient amount of relevant world knowledge, such as general knowledge about locks and mechanical equipment. Deep comprehension consists of the construction of this referential situation model, whereas shallow comprehension is limited to the surface code and textbase. The situation model is retained in memory much longer than the textbase and the surface code, assuming that the comprehender has adequate world knowledge to build a situation model.

The pragmatic communication level refers to the information exchange between speech participants. In a two-party oral conversation, the two speech participants take turns speaking while pursuing conversational goals. There may be additional participants in a conversation, such as side participants in the circle of conversation and bystanders who are outside of the circle. Speech acts are crafted in a fashion that is sensitive to the common ground (shared knowledge) between speech participants, and linguistic cues differentiate given (old) information in the dialog history from new information. The cognitive representation of a spoken utterance can be quite complex when there are several communication channels between multiple participants (sometimes called agents) in a conversation. When printed text is read and comprehended, the pragmatic communication is somewhat simplified, although there are vestiges of oral communication and multiple communication channels in textual matter. For example, there is communication between the reader and writer, between the narrator and audience, and between agents in embedded dialogues within the text content. Text comprehension improves when readers are sensitive to the communication channel between author and reader.

Discourse genre is the type of discourse–such as narration (stories), exposition, persuasion, and so on. Discourse analysts have proposed several different discourse classification schemes, which are organized in a multilevel hierarchical taxonomy or in a multidimensional space (a set of features or levels of representation that are potentially uncorrelated). The Macaulay excerpt above would be classified as expository text. Narrative text is normally much easier to comprehend than expository text because narrative has a closer affinity to everyday experiences.

Deep comprehenders construct rich representations at the levels of the situation model, pragmatic communication, and discourse genre, whereas the textbase and surface code have a secondary status. Paradoxically, the examinations that students normally receive tap the surface code and textbase rather than the deeper levels. Teachers generally ask students to recall explicit content or to answer multiple-choice questions that tap word recognition, definitions, or attributes of concepts. One way of promoting deep comprehension is to compose exams with questions that emphasize the situation model, inferences, reasoning, and other aspects of the deeper levels. Since the late 1980s, researchers have advocated a shift in assessment standards to encourage deep comprehension.

Discourse Coherence

Coherence is achieved both within and between the levels of representation when comprehension occurs. This means that there should be no serious coherence gaps within a particular level and there should be harmony between the levels of representation. A coherence gap occurs within the situation model, for example, when an incoming clause (the clause currently being read) in the text cannot be linked to the previous content on any conceptual dimension, such as causality, temporality, spatiality, or motives of characters. Simply put, a coherence gap occurs when information is mentioned out of the blue. Similarly, there may be coherence gaps at the levels of the surface code, textbase, pragmatic communication, and discourse genre. Regarding coherence between levels, the elements of the representation at one level need to be systematically related to the elements at another level. Comprehension suffers, for example, when there is a clash between the textbase and situation model. If the text stated, "The key is turned after the cylinder rotates," there would be a discrepancy between the order of events in the correct situation model (the key is, in fact, turned before the cylinder rotates) and the explicit textbase, which reverses the correct order.

Comprehension breaks down when there are deficits in world knowledge or processing skills at particular levels of representation. When there is a deficit at one level of representation, the problems can propagate to other levels. For example, nonnative speakers of English may have trouble processing the words and syntax of English, so they may also have trouble constructing the deeper levels of representation. Readers have trouble comprehending technical texts on arcane topics because they lack world knowledge about the topic. A barrier in constructing the situation model ends up confining the processing to the surface code and textbase levels, so the material will soon be forgotten.

While studying a test about heart function, McNamara et al. (1996) documented an intriguing interaction among readers' knowledge about a topic, coherence of the textbase, and the level of representation that was being tapped in a test. The readers varied in the amount of prior knowledge they had about the topic covered in the text. In the study, half of the readers read a text with a coherent textbase. That is, clauses were linked by appropriate connectives (e.g., therefore, so, and), and the topic sentences, headings, and subheadings were inserted at appropriate locations. The other texts had low coherence due to violations in the insertion of connectives, topic sentences, headings, and subheadings. The tests tapped either the textbase level of representation (which included recall tests) or the situation level (which included tests of inferences and answers to deep-reasoning questions).

The results of the McNamara study were not particularly surprising for low-knowledge readers. For these readers, texts with high coherence consistently produced higher performance scores than texts with low coherence. The results were more complex for the readers with a high amount of prior knowledge about the heart. A coherent textbase slightly enhanced recall, but actually lowered performance on tasks that tapped the situation model. The gaps, or breaks in temporality, spatiality, and causality, in text coherence forced the high-knowledge reader to draw inferences, construct rich elaborations, and compensate by allocating more processing effort to the situation model. In essence, deep comprehension was a positive compensatory result of coherence gaps at the shallow levels of representation.

Comprehension Calibration

One counterintuitive finding in comprehension research is that most children and adult readers have a poor ability to calibrate the success of their comprehension. Comprehension calibration can be measured by asking readers to rate how well they comprehend a text, and then correlating such ratings with comprehension scores on objective tests. These correlations are always either low or modest (r =.2 to.4), which suggests that college students have disappointing comprehension calibration. Another method of calibrating comprehension is to plant contradictions in a text and observe whether readers detect them. Such contradictions are not detected by a surprising number of adult readers. Instead, there is a strong tendency for readers to have an illusion of comprehension by adjusting their expectations at handling the surface code and textbase. Readers need to be trained to adjust their metacognitive expectations and strategies to focus on the deeper levels.

Classroom discourse is too often skewed to the shallow rather than the deep end of the comprehension continuum. Teachers typically follow a curriculum script that covers definitions, facts, concepts, attributes of concepts, and examples. This content is at the lower levels of Benjamin Bloom's taxonomy of cognitive objectives. Teachers rarely attempt to encourage Bloom's higher levels of inference, synthesis, integration, and the application of knowledge to practical problems.

Discourse Mechanisms that Promote Deep Comprehension

There are some methods of improving deep comprehension and learning by invoking discourse processing mechanisms, including: (1) constructing explanations, (2) asking questions, (3) challenging a learner's beliefs and knowledge, and (4) tutoring.

Constructing explanations. Good comprehenders generate explanations as they read text or listen to lectures. These explanations trace the causes and consequences of events, the plans and goals of agents (humans, animals or organizations), and the logical derivations of assertions. The questions that drive explanations are why, how, what-if, and what-if-not questions. For example, a deep comprehender might implicitly ask the following questions while reading the cylinder lock text: Why would the person turn the key to the right? How does the bolt move back? What causes the cam to rotate? What if the pins don't rise? Students learn much more when they construct these explanations on their own (selfe-xplanations) than when they merely read or listen to explanations.

Asking questions. Students should be encouraged to ask and answer deep-reasoning questions to help them construct explanations. Unfortunately, students are not in the habit of asking many questions, and most of their questions are shallow. A typical student asks only .11 questions per hour in a classroom, and less than 10 percent of student questions involve deep reasoning. When students are trained how to ask good questions while reading or listening to lectures, their comprehension scores increase on objective tests. Teachers rarely ask deep-reasoning questions in classroom settings, so it would be prudent to improve the questioning skills of teachers. Challenging the learner's beliefs and knowledge. One of the easiest ways to get students to ask questions is to challenge one of their entrenched beliefs, and thereby put them in cognitive disequilibrium. Suppose, for example, that a teacher expresses the claim that overpopulation is not a significant problem to worry about. This will normally stimulate a large number of student questions and counterarguments. Research on question asking has revealed that genuine information-seeking questions are inspired by contradictions, anomalies, incompatibilities, obstacles to goals, salient contrasts, uncertainty, and obvious gaps in knowledge. Therefore, one secret to eliciting student questions is to create cognitive disequilibrium and then provide useful information when students ask questions.

Tutoring. One-to-one human tutoring is superior to normal learning experiences in traditional classroom environments. This advantage cannot entirely be attributed to the possibility that tutors are more accomplished pedagogical experts than teachers. Peers often do an excellent job serving as tutors. Normal tutors rarely implement sophisticated pedagogical strategies, such as the Socratic method, building on prerequisites, error diagnosis and repair, or modeling-scaffolding-fading. It is the discourse patterns in normal tutoring that explain much of the advantages of tutoring over the classroom. The discourse in tutoring emphasizes collaborative problem solving, question asking and answering, and explanation building in the context of specific problems, cases, and examples. There is a turn-by-turn collaborative exchange (speakers take turns talking) in tutoring that would be impractical to implement in the classroom.

In summary, research in discourse processing can help solve some of the pressing challenges in education. Discourse plays an important role in helping the learner shift from shallow to deep comprehension, and from being a fact collector to being an inquisitive explainer.