One of the strongest predictors of how easily and well a person will learn a topic is their prior knowledge about it. The more one already knows, the easier it is to learn more. Because of this fact, students often struggle more with introductory courses, where they know little about a field, than with advanced ones, where they are adding to what they already know. There is a controversy going on in education circles about the role of knowledge versus skills. Should we teach students background knowledge, or should we focus on developing abstract skills, like reading and critical thinking? The evidence shows that prior knowledge is necessary for effective reading and critical thinking, so some educators have advocated for an emphasis on memorization of facts and information. That approach, though, is not sufficient. Cognitive research shows that useful prior knowledge is more than an accumulation of facts. Let me lay out what the research shows.
A schema refers to organized knowledge about an event. The more common an event, the more extensive your schema is about that event. Schemas[1] tell us what conditions must exist for an event to occur, what to expect at the event, and how to understand what is happening during the event; later, they help us to recall the event. The typical example we cognitive psychologists use is dining at a restaurant. If you are going to a restaurant, you know you should be hungry and have a means to pay for the meal. At a fine dining restaurant, you would likely make a reservation, check in with the host, be seated and given menus, order and get your food, eat it, pay for the meal, and leave. At a fast food place, you would expect to approach the counter, order, pay and get your food, find a table, eat, throw away your trash, then leave. Imagine that you were at a fancy restaurant and after you ordered, the server asked you to pay for your meal before getting your food. You’d be shocked, even though that is what you’d do at a fast food place.
When we teach, we aren’t trying to instill unrelated pieces of information in our students; we are trying to build schema, a coherent, connected understanding of concepts. The best way to develop schematic understanding in students is still unknown, but it is something that effective teachers do better than less effective ones. It certainly helps to present information within a coherent framework rather than presenting it as unrelated facts for the students to learn. Even developing schematic knowledge, however, is not enough if students aren’t able to activate and use the knowledge appropriately.
Bransford and Johnson (1972) performed a classic set of experiments on schemas, one of which became a popular teaching demonstration. I’ve seen it done at several workshops, but typically the presenters miss a key point about it. Let’s do the demonstration and then discuss it. Read the paragraph below and think to yourself how easy this passage is to understand and how well you could memorize it if required to.
The procedure is actually quite simple. First you arrange items into different groups. Of course, one pile may be sufficient depending on how much there is to do. If you have to go somewhere else due to lack of facilities that is the next step, otherwise, you are pretty well set. It is important not to overdo things. That is, it is better to do too few things at once than too many. In the short run this may not seem important, but complications can easily arise. A mistake can be expensive as well. At first, the whole procedure will seem complicated. Soon, however, it will become just another facet of life. It is difficult to foresee any end to the necessity for this task in the immediate future, but then, one never can tell. After the procedure is completed one arranges the materials into different groups again. Then they can be put into their appropriate places. Eventually they will be used once more and the whole cycle will then have to be repeated. However, this is part of life. (Bransford & Johnson, 1972, p. 722)
Now, on a scale of 1 to 7, rate how easy this passage is to comprehend, with 1 being very hard and 7 very easy. Next, if I were to ask you to recall as much of the passage verbatim from memory, how well do you think you could do? You probably rated the passage as difficult to comprehend and predicted that you would have a hard time remembering it unless you realized that it’s about washing clothes. Reread the passage with idea that it is about washing clothes and see whether it is easier to comprehend and recall.
Bransford and Johnson had participants read this passage, rate its comprehension, and recall as much of the passage as they could. They did so in one of three conditions. In the No Topic control condition, participants were not told the topic of washing clothes. In the Topic Before condition, they were told the topic before they read the passage. Finally, in the Topic After condition, participants were told that the passage was about washing clothes only after they read the passage. Figure 1 shows the average results (in percentages) for comprehension ratings and recall.
First, compare the No Topic and Topic Before conditions. Knowing the topic ahead of time greatly increases ease of comprehension and recall of the passage. Even though both groups had similar knowledge about washing clothes, if the knowledge was not activated, then comprehension and recall suffered. Now compare the Topic After group to both the No Topic and the Topic Before groups. The results for the Topic After group are similar to those for the No Topic group and much worse than for the Topic Before group. In other words, activating the relevant schematic knowledge after reading the passage was no help at all in comprehending or recalling the passage.
This latter point is critically important for teaching, and it is the one presenters of this demonstration typically overlook. Teachers and textbooks often present a series of facts and then try to tie them all together with an overarching concept. This practice makes it hard for students to understand and learn material. The teachers, of course, know what the overall concept is, but the students don’t. It is easy for teachers to forget that students don’t automatically grasp the big picture.
For optimal learning, teachers need to provide an overall framework for students first, then flesh it out with specific information. Teachers need to make sure that all the relevant information is activated for students to comprehend and learn new concepts. At the beginning of class, teachers should spend some time reviewing concepts learned previously to ensure that students have activated the relevant information. To promote transfer of knowledge, teachers should instruct students to identify new situations in which schematic information is useful and should be activated. If the knowledge is not activated, it won’t be helpful to students. Bransford and Johnson put it this way: “Prior knowledge of a situation does not guarantee its usefulness for comprehension. In order for prior knowledge to aid comprehension, it must become an activated semantic context” (p. 724).
Getting back to the controversy of knowledge versus skills, prior knowledge is critical for skill development, but just having prior knowledge is not enough. Students need to have their knowledge organized into schemas, and the relevant schemas must be activated. In addition to developing knowledge schemas, students must learn to recognize when it is appropriate and useful to activate them. How prior knowledge is taught is critical to its future usefulness.
[1] The proper plural of schema is schemata, but since about the 1980s we crude and unrefined cognitive psychologists have used schemas as the plural.
Reference
Bransford, J. D., & Johnson, M. K. (1972). Contextual prerequisites for understanding: Some investigations of comprehension and recall. Journal of Verbal Learning & Verbal Behavior, 11(6), 717–726. https://doi.org/10.1016/S0022-5371(72)80006-9
Stephen L. Chew, PhD, is a professor of psychology at Samford University. Trained as a cognitive psychologist, he endeavors to translate cognitive research into forms that are useful for teachers and students. He is the recipient of multiple awards for his teaching and research. Author contact: slchew@samford.edu.
