What Do Scientists Know About How We Learn?

A brief summary of the most important principles of learning and memory
by Daniel B. Willingham

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There are three things we would really like to know about how people learn: (1) how can you get people to learn new things; (2) how can you ensure that people can apply what they’ve learned; (3) how can you ensure that people will retain what they have learned for a long time?

How can you get people to learn new things? The most important factor in memory is how the person thinks about the to-be-learned material. For example, most people think that they know what a penny looks like, but how many know a penny’s features in any detail? Which way does Lincoln face? Where does the year appear? Despite exposure to thousands of pennies over your lifetime it’s unlikely that you have learned this information. Why? Because when you look at a penny, you don’t think about these details. You think mostly about color and size, because color and size distinguish pennies from other coins. Thus the first principle of memory is that we remember what we think about, not necessarily what is in the environment, even if we’re exposed to it repeatedly.

That point obviously raises the question of what determines what we think about. What you think about when you see or hear something new depends largely on what you already know. In general, knowledge builds on knowledge. The more you know, the easier it is to learn new things. As an example, consider this sentence: “The fielder shagged the fly and the runner tried to double up from third, but the cut-off man rifled it home and the ump called him out.” This sentence is unintelligible if you don’t have some background knowledge about baseball, but if you do, it’s quite sensible. Thus the second principle is that what we think about is determined by what we already know. If you know baseball, what you think about when you hear this sentence is much different than what you think about if you don’t know baseball. Needless to say, when the sentence is comprehensible, it’s much easier to learn and remember.

How can you ensure that people can apply what they’ve learned?Psychologists have discovered that specificity is a basic characteristic of memory. Material is usually remembered best in the same context in which it was learned; that is, when people think about the material in the same way. For example, suppose you were asked to remember the word “piano” and it was presented in the sentence, “The overweight moving men struggled to heave the PIANO up the steep staircase.” Now suppose I later test your memory for this word by giving you this hint: “One of the words was something that can produce music.” The hint would be useless. I encouraged you to think about one feature of a piano (heaviness) when you first saw it, and then later try to give a hint that emphasizes another feature of a piano (music-producing). The fact that your memory system cannot use that hint leads us to a third principle of memory: memory is specific.

If memory is specific, how can we be sure that new material that is learned can be applied to a variety of situations?
How can you retrieve the right information from memory (piano) if you learned it in one context (it’s heavy) but are now presented with another context (it produces music)? The best bet to make memories flexible is to see the to-be-learned material in a number of different situations. For example, if you are trying to learn a theorem in geometry, it’s best to work a number of different types of problems requiring the theorem. That will make it more likely that you can apply it to novel, never-seen-before problems.

At the same time, it is important to be explicit about what is being learned. If there is a general theorem, it is essential that the theorem be stated in addition to being illustrated with examples. Giving many examples and trusting that people will, in time, figure out the general principle is a mistake. People may figure it out, but it will take much much longer than if you simply tell them the principle. Indeed, sometimes they will never figure out the principle. Most Americans have seen hundreds of movies, but very few can tell the general principles of how an American movie is plotted. (Pick up any book on writing screenplays, and you will see that these principles exist, and are closely followed in any American movie). Repeated exposure to examples does not necessarily mean that the general principles will be learned.

How can you ensure that people will retain what they’ve learned for a long time?
If you take Spanish in high school, how much will you remember ten years later? How about fifty years later? Recent studies of memory for high school Spanish (and mathematics, and other material) have shown that two factors are crucial to the longevity of memories. The first is practice. People who studied Spanish over several years had a core knowledge of Spanish that they did not forget even after fifty years. That knowledge was essentially permanent. The second factor contributing to memory’s longevity is that the practice be distributed over time.

If you cram, you may remember information for a week or two, but distributing learning sessions is much more effective for maintaining the memories for years. Thus, the fourth principle of memory is that memory is long-lasting if practice is sustained and distributed in time. The implications of these principles of memory are straightforward. First, we must be aware that students will not necessarily remember what we want them to remember. They remember what they think about. If a lecture or a project leads them to think about irrelevant or incorrect material, that is what they will remember. Clearly, this doesnt’ mean that one must try to tightly prescribe students’ thinking every moment of the day, but it should be a guiding principle. Second, the more students know, the easier it will be for them to learn new material. Third, learning is most generalizable if students see material in a variety of different contexts, but general principles should be provided along with examples. Finally, practice is important, but practice must be distributed over time for it to be effective. Naturally, it is easier to draw implications than to actually implement them. Other considerations come into play in the classroom. Nevertheless, if one is considering how people best learn and remember new material these principles are well-established.

From Common Knowledge, Volume 12, Numbers 1& 2, 1999
© 1999 Core Knowledge Foundation