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Let me ask you a simple question that stumps just about everyone: What image appears on the back of a $10 bill? Don't get down on yourself if you don't know the answer. I've asked this same question of thousands of psychology students over the years and hundreds of psychologists at teaching conferences. Invariably, no more than a small handful of people know the answer. Stumped? It's the U.S. Treasury building.
The more intriguing question is why so few people know the image that appears on the back of a unit of currency they have handled countless times in their lives and which at this very moment may be sitting in their wallets or pocketbooks. My students know the answer to this one: "It's because we don't need to know what's on the back." All that matters in common use is the denomination on the front of the bill. Students intuitively recognize that we don't bring into long-term memory everything we may have seen or experienced.
The study of human memory is one of the most dynamic areas of study in psychology. Although we have not unlocked all the mysteries of memory, we do know that memory depends on encoding, the process by which we first bring information into memory in a form that can stored and later retrieved. So if you have never encoded the image on the back of the $10 bill, there's no memory to retrieve.
The principle of encoding has implications for helping students become more effective learners. Students need to encode the important information the instructor conveys in class or which they read in their textbooks. Basically, they need to develop the ability to extract key points, concepts, and ideas that constitute the important information they need to learn. In our laboratory research on textbook pedagogy, we demonstrated the learning benefits of signaling key concepts by highlighting them in the margins of the textbook.* This technique, called concept signaling, helps students gauge that they are getting the main points as they read through the text.
Students can benefit from applying the principle of encoding to their study habits. Here's a straightforward suggestion to students to help them get the most out of reading their textbooks: Stop yourself after every paragraph you read and pose the following questions to yourself about what you have just read: What was the main point or points? What was the author trying to say? What am I expected to know? Reciting the answers to these questions and then jotting them down for later review helps consolidate new learning and provides the basis of a study sheet for preparing for exams. You can also use other signaling tools in your textbooks by paying particular attention to headings, survey questions, and review sections that highlight major topics and key concepts covered in the text. Applying the principle of encoding helps transform passive reading into active learning. It may require more work than just casual reading without pausing and self-questioning, but it is likely to pay off many times over with better retention of information and better grades.
*Adapted from J.S. Nevid & J. L. Lampmann, "Effects on content acquisition of signaling key concepts in text material," published in Teaching of Psychology, 2003
