Background Knowledge: Implications for the Classroom

How to Evaluate Which Knowledge to Instill

We might well ask ourselves, Which knowledge should students be taught? This question often becomes politically charged rather quickly. When we start to specify what must be taught and what can be omitted, it appears that we are grading information on its importance. The inclusion or omission of historical events and figures, playwrights, scientific achievements, and so on, leads to charges of cultural bias. A cognitive scientist sees these issues differently. The question, What should students be taught? is equivalent not to What knowledge is important? but rather to What knowledge yields the greatest cognitive benefit? This question has two answers.

For reading, students must know whatever information writers assume they know and hence leave out. The necessary knowledge will vary depending on what students read, but most observers would agree that a reasonable minimum target would be to read a daily newspaper and to read books written for the intelligent layman on serious topics such as science and politics. Using that criterion, we may still be distressed that much of what writers assume their readers know seems to be touchstones of the culture of dead white males. From the cognitive scientist's point of view, the only choice in that case is to try to persuade writers and editors at the Washington Post, Chicago Tribune, and so on to assume different knowledge on the part of their readers. I don't think anyone would claim that change would be easy to bring about. It really amounts to a change in culture. Unless and until that happens, I advocate teaching that material to our students. The simple fact is that without that knowledge, they cannot read the breadth of material that their more knowledgeable schoolmates can, nor with the depth of comprehension.

The second answer to the question applies to core subject matter courses. What should students know of science, of history, of mathematics? This question is different than the first because the uses of knowledge in these subject areas are different than the uses of knowledge for general reading. Reading requires relatively shallow knowledge. I don't need to know much about a nebula to understand the word when it's used in a newspaper article; but if I'm studying astrophysics, I need to know much more. Students can't learn everything, so what should they know? Cognitive science leads to the rather obvious conclusion that students must learn the concepts that come up again and again—the unifying ideas of each discipline. Some educational thinkers have suggested that a limited number of ideas should be taught in great depth, beginning in the early grades and carrying through the curriculum for years as different topics are taken up and viewed through the lens of one or more of these ideas. From the cognitive perspective, that makes sense.

Be Sure That the Knowledge Base Is Mostly in Place When You Require Critical Thinking

Our goal is not simply to have students know a lot of stuff—it's to have them know stuff in service of being able to think effectively. As emphasized in this chapter, thinking critically requires background knowledge. Critical thinking is not a set of procedures that can be practiced and perfected while divorced from background knowledge. Thus it makes sense to consider whether students have the necessary background knowledge to carry out a critical thinking task you might assign. For example, I once observed a teacher ask her fourth-grade class what they thought it would be like to live in a rain forest. Although the students had spent a couple of days talking about rain forests, they didn't have the background knowledge to give anything beyond rather shallow responses (such as "It would be rainy"). She asked the same question at the end of the unit, and the student's answers were much richer. One student immediately said she wouldn't want to live there because the poor soil and constant shade would mean she would probably have to include meat in her diet—and she was a vegetarian.

Shallow Knowledge Is Better Than No Knowledge

Some of the benefits of factual knowledge require that the knowledge be fairly deep—for example, we need detailed knowledge to be able to chunk. But other benefits accrue from shallow knowledge. As has been noted, we usually do not need to have detailed knowledge of a concept to be able to understand it s meaning in context when we're reading. For example, I know almost nothing about baseball, but for general reading, a shallow definition such as "a sport played with a bat and ball, in which two teams oppose one another" will often do. Of course deep knowledge is better than shallow knowledge. But we're not going to have deep knowledge of everything, and shallow knowledge is certainly better than no knowledge.

Do Whatever You Can to Get Kids to Read

The effects of knowledge described in this chapter also highlight why reading is so important. Books expose children to more facts and to a broader vocabulary than virtually any other activity, and persuasive data indicate that people who read for pleasure enjoy cognitive benefits throughout their lifetime. I don't believe it is quite the case that any book is fine "as long as they're reading." Naturally, if a child has a history of resisting reading, I'd be happy if she picked up any book at all. But once she is over that hump, I'd start trying to nudge her toward books at the appropriate reading level. It's rather obvious that a student doesn't gain much from reading books several grades below her reading level. I'm all for reading for pleasure, but there are fun, fascinating books at every reading level, so why not encourage age-appropriate materials? It's just as obvious that a too difficult book is a bad idea. The student won't understand it and will just end up frustrated. The school librarian should be a tremendous resource and ally in helping children learn to love reading, and she is arguably the most important person in any school when it comes to reading.

Knowledge Acquisition Can Be Incidental

The learning of factual knowledge can be incidental—that is, it can happen simply by exposure rather than only by concentrated study or memorization. Think about all you have learned by reading books and magazines for pleasure, or by watching documentaries and the news on television, or through conversation with friends. School offers many of the same opportunities. Students can learn information from math problems, or through sample sentences when they are learning grammar, or from the vocabulary you use when you select a classroom monitor. Every teacher knows so much that students don't. There are opportunities to fold this knowledge into each school day.

Start Early

At the end of the last section I noted that a child who starts behind in terms of knowledge will fall even farther behind unless there is some intervention. There seems to be little doubt that this is a major factor in why some children fare poorly in school. Home environments vary a great deal. What sort of vocabulary do parents use? Do the parents ask the children questions and listen to the children's answers? Do they take their child to the museum or aquarium? Do they make books available to their children? Do the children observe their parents reading? All of these factors (and others) likely play a role in what children know on their first day of school. In other words, before a child meets her first teacher, she may be quite far behind the child sitting next to her in terms of how easy it is going to be for her to learn. Trying to level this playing field is a teacher's greatest challenge. There are no shortcuts and no alternatives to trying to increase the factual knowledge that the child has not picked up at home.

Knowledge Must Be Meaningful

Teachers should not take the importance of knowledge to mean that they should create lists of facts—whether shallow or detailed—for students to learn. Sure, some benefit might accrue, but it would be small. Knowledge pays off when it is conceptual and when the facts are related to one another, and that is not true of list learning. Also, as any teacher knows, such drilling would do far more harm by making students miserable and by encouraging the belief that school is a place of boredom and drudgery, not excitement and discovery. Most teachers also know that learning lists of unconnected facts is pretty hard to do. But what is a better way to ensure that students acquire factual knowledge, now that we've concluded it's so important? In other words, why do some things stick in our memory whereas other things slip away? That is the topic of the next chapter.