Learning Memories

Teaching memories is simple -- if you want someone to store some information in memory, just tell them. For example, if I want you to know my address, I simply tell you that my house number is 10. That doesn't quite end the story -- as all students know, rehearsal is important too. But it's still basically a simple story -- hear (or read) the information, then rehearse.

You might have read about "new" teaching techniques, such as "discovery" learning, which are supposed to be superior to just telling students what you want them to learn. They might be better, but not for teaching memory. My student Helene once did this experiment invesigating the effectiveness of discovery learning for memory. The subjects were presented with unfamiliar words. Half the subjects first tried to guess how the words were pronounced. They were told if their guesses were right or wrong, and after two wrong guesses they were told the correct pronunciation. The other half of the subjects were just told the correct pronunciation.

The first group of subjects engaged in discovery learning; the second group didn't. In every experiment I have ever read, discovery learning was the winner over rote memorization. But not this experiment -- the discovery group did worse. Why? The subjects were just trying to learn how a word was pronounced. That's memory. The second group got the information in the perfect format -- they were told the correct answer. The discovery group eventually got the information in the right format. But producing wrong pronunciations was a waste of their time and energy. So they worked harder, took longer, and did no better.

Why did they do worse? The explanation is not difficult to find. Their wrong answers were what psychologists call interference. When it came time for the subjects to try to recall the correct pronunciation, the memory for the wrong answer interferred with the memory for the right answer. Interference is a well-known and completely-accepted principle of memory.


Testing memory is also basically simple. The straightforward use of memory is for recall or recognition. Therefore, to test for memory of some piece of information, simply ask students to recall that information or recognize that information. That of course is what most tests do in our educational system. You can ask students to use the information, but then they might know the information but be poor at using it. So that isn't the best test of memory.

In mathematics, the test is mathematical problems. But before the test, the students are taught formulas and procedures for solving the problems, which they memorize. On the test, they just recall the formulas and procedures. So most students use memory for math tests. Or at least they try. Actually, memory doesn't work very well for math, which is why so many people have trouble with math.

So, in our educational system today, most exams reward conscious learning.

The Educational System Today

If you haven't noticed yet, let me now point out that our educational system is ideal for teaching memory, and its tests are ideal for testing memory. I haven't yet talked about how to teach and learn mental models, but the short story for now is that the educational system doesn't do that.

Why is it ideal for memory? As always, consciousness dominates. Memories are closely intertwined with consciousness, so we know about them and they get our attention. The assumption, unfortunately, is that they are the only type of knowledge. So when people design an educational practice, they design it to teach memory.

The Problems of Learning Conscious Knowledge

Okay, at least our educational system teaches conscious knowledge. What's so bad about that? As it turns out, a lot.

The problem of understanding. Teachers universally agree that students should understand what they are learning. However, conscious knowledge has almost nothing to do with understanding. I don't have to understand anything about James or functionalism to store and recall that James is a functionalist. I didn't have to understand anything about antacids or appendicitis to store, recall, and use the knowledge that I shouldn't take an antacid if I have a stomach ache because I might have appendicitis. When students are told a formula for calculating standard deviation, or correlation, they don't have to understand standard deviation or correlation to remember and use these formulas.

Instead, to say you understand something usually means that you have a mental model of it, actually an accurate mental model that makes correct predictions.

This difference between conscious knowledge and understanding is neatly captured in a story by John Holt (How Children Learn). Holt was good at machines, but when he first saw a loom, he was stumped. All of the parts of a loom were visible, so he could see the whole loom and know exactly what was connected to what. In terms of conscious knowledge, he knew exactly how a loom was built. But he didn't understand the loom. Later, the pieces of the loom started appearing in his mind one by one. As each piece appeared, he understood it. When they had all appeared, he understood the loom. When he was done, he still had the same visual image, but now it was accompanied by understanding.

Tests rarely require understanding. Students are asked to recall or recognize that James is a functionalist. Students are asked to calculate standard deviation; they are not given problems that can be solved only by understanding standard deviation.

So, our educational system teaches conscious knowledge, not understanding. This is because it does not teach mental models.

The problem of using the information. In theory, conscious knowledge is very flexible and can be used in a variety of ways. In practice, if you don't understand your conscious knowledge, it won't be very useful for anything other than communicating it to others or taking a typical test of recall or recognition.

For example, to teach students what a theory was, I gave them an excellent lecture, differentiating theories from other types of information in the sciences. They were always able to regurgitate this information on my test. But one test, I asked the students to give me an example of a theory of happiness. That would seem to be the simplest use of the information they had been taught, but only 4 out of 130 students could do this. Guess what? The students did not really understand what a theory was, and I wasting their time and mine.

Or suppose I am teaching how the mind works. If students are going to try to use their mind effectively, or predict what other people will be thinking, or decide how to change other people's thoughts, they need a mental model of the mind.

Or, if I teach you conscious knowledge of the rules for good bidding at bridge, you will be able to teach others. As discussed in Chapter 6 though, you won't bid well. If I give you experience from which you develop a rich mental model of bidding, you will bid well but will have a lot of difficulty communicating your skill to others. I faced this problem in teaching students to be good experimenters. I developed a method that did work -- at the end of the semester, they were skilled experimenters. But they had no sense that they had learned anything, which was a problem for me when they filled out my teacher evaluations.

The problem of retention. The third problem with teaching just conscious knowledge is that information is quickly forgotten -- one of the basic facts of memory is that memories are forgotten quickly.

And it takes no keen observation to realize that this is exactly what happens in our educational system. Students are taught conscious knowledge in the optimal way, and they study it themselves in the optimal way. They are then tested for their conscious knowledge, and this test reveals that they learned what they were supposed to.

Then they forget it. I know one very good student who learned the names of all of the bones for a test but now can name only the shin bone. I know another very good student who learned the distance of each planet from the sun for a test, but now has no idea which planets are closest to the sun. A researcher tested how much students retained from a college class in cognitive psychology. After two years, they retained only a little; after five years, there was no sign of any knowledge.

But I shouldn't be telling you anything new. College students tell me, over and over again, that they learn the material for the final exam and forget it before the next semester begins.

And so, I need to amend my claims. The educational system is ideal for teaching the short-term retention of conscious knowledge. And it is ideal for teaching conscious knowledge that cannot be accompanied by understanding. But it usually fails for the long-term retention of conscious knowledge. Teachers are exactly right, that understanding is critical. Without understanding -- a mental model -- conscious knowledge usually cannot be used and almost certainly will be forgotten.

The Failure of Current Education

How well does our educational system work? In a way, this is an impossible question to ask. The real question is, how it does compare to how it could do if it tried to teach mental models. I can envision how much students would know if they learned in a way that suited the development of mental models. Compared to that, our educational system is simple horrible.

Alas, I cannot prove how much children would learn if they were taught properly. But my judgment is not just idle speculation. I know how much I learn when I am using methods suited to the development of mental models, compared to when I am just memorizing.

But many people have at least a vague sense that our educational system is not working as well as it should. They can tell, because our educational system is not merely suboptimal, it is truly abysmal. Too often, the evidence suggests that students don't learn anything (or would know just as much if they did not attend school). For example, in one of my experiments, 1/3 of the college students did not know that Albany was the capitol of New York. These students all lived in the state of New York.

If you look at understanding and the retention of skills, the picture is even worse. In my class on how to perform experiments, all of the students had previously taken a statistics course. Most students did not remember their statistics and were extraordinarily glad to hear that they did not have to remember statistics and that I would teach them everything they needed to know. I had no choice -- I couldn't expect them to know statistics, because they didn't. I let one student take the course even though she had not yet taken statistics. At the end of the course, I thought to ask her supervisor how she had done. The only difference between her and the other students was that she did a lot more different statistical analyses of her data, as if she enjoyed doing the statistical tests. So the students do learn something in statistics -- to dislike it.

Even the best of students do not learn much. I frequently ask people (usually Ph.D.'s) about Lincoln's Gettysburg address. They can usually tell me details (good memory), but no one knows why it is famous or important. My clue -- a Chicago paper called Lincoln a liar -- doesn't help. The Gettysburg Address is one of the defining moments in the history of America, shaping our fundamental belief of what our country is, and no one knows. I ask about Ben Franklin's kite experiment, and again I get facts. I ask why the key would contain electricity, and no one knows. In other words, they don't understand the fundamental idea of his experiment. Some say that the kite was hit by lightning, but most know that can't be true, leaving them very puzzled as to why there would be any electricity present in the key. I ask people about rainbows, and they tell me about prisms. Good, but I ask them, "If you are looking at a rainbow, where is the sun?" They don't know. The prism model suggests that the sun would be behind the clouds, but light from the sun wouldn't get through a dark cloud.

I saw a room full of graduate students puzzle over why there are two wires rather than one leading to an electrical appliance. One student finally came up with the idea that the second wire carried the used-up electrons out of the appliance. The other students agreed that was a good explanation. The exception, the only student that knew the answer, was by far the least academically talented student in the room.

If these things were taught, the failure of education is that the students did not learn. But most of these aren't even taught. The failure of education is that most of time, no effort is made to even teach the things that are worthwhile. Of course, the teachers and textbook writers are products of our educational system and don't know the answers either. But mental models also aren't the type of thing our educational system can teach, and they aren't the kinds of things students know how to learn. Our educational system teaches only conscious knowledge.

And the stories continue on. Researchers tried a new method of teaching writing. This new method produced no observable improvement in writing ability. But it was as good as the standard method, which also produced no observable improvement. I think a fair assessment of our student's writing ability is that have not learned anything. I did not have the basic concept of editing until I was 24.

Researchers asked a physics teacher to give the students some problems that did not require mathematical calculations, but instead just required an understanding of the basic concepts. The teacher said the problems were too easy, but he nonetheless agreed to include them on the test. The students performed miserably and the teacher was shocked.

A look at students' thinking skills is just as dismal. I twice had a class discussion about drawing morals from the story of Solomon and the two mothers. There are a lot of potential morals. Its impossible to think of them all, and perhaps difficult to construct the best one. But it should be easy to think of several. One student could generate conclusions almost at will, spinning off 3 or 4 and stopping only because I didn't call on him any more. No one else could draw any implications.

Or consider this problem. Suppose the airlines were found to be overpricing their tickets. As punishment, they were forced to fly people for free for the upcoming month of June. What will happen? Students say they will take a free vacation that month. Well, there are a variety of different things that might happen, but one of them is not everyone taking a free airplane flight -- the airlines will not increase their flights to accommodate free passengers. The point is, students cannot think of the implication of an action. I sometimes worry about lawmakers too.

Still ranting. Does anyone think that students are learning? One book I read was the memoirs of a principal. He described his experiences with difficult children -- delinquents really -- and his successes in getting them to be contributing members of society. He seemed to be a wonderful principal. But, there was nothing in the book about learning. In one high school classroom where I was substitute teaching, the teacher had a sign on the wall that said "The students won't remember what we teach them, but they will remember how we treat them." Good advice. But if the students won't remember what we teach them, why are we sending them to school? One writer in a teachers' magazine complained that employers care more about whether a student has previous work experience than the student's grades. The writer bemoaned the problem of getting students to get good grades when they would be rewarded more for working at McDonalds. I drew the opposite conclusion -- employers know students do not learn anything useful in school.

The schools create the illusion of learning. If students study for a test, they will do better on the test than if they don't study. But if you look at learning of useful information, or if you look at learning beyond the test, or if you look at learning of useful thinking skills, the evidence suggests that very little learning occurs in schools. Okay, students learn to read in school. But that's a habit; the great deficit of education is teaching mental models. And according to the statistics collected in Massachusetts, the literacy rate was higher before compulsory education was begun than at any time afterwards.

Finally, it is said that sending people to prison accomplishes nothing other than teaching them to be criminals. Great. Prisons can teach people, but schools can't. (Still ranting.)


I think the educational system today is abysmal. My view might be extreme, but many agree there are serious problems with education.

Why? The educational system assumes that there is only one type of knowledge, conscious knowledge. In fact, there are several different types of knowledge, learned in different ways and having different uses. Learning mental models is the most important of the four, not conscious knowledge. Mental models are useful and lead to understanding; conscious knowledge is not that useful and anyway is quickly forgotten without a supporting mental model.

However, education is viewed as just the communication and retention of information, which is to say, learning conscious knowledge. The standard methods of teaching are telling the students what you want them to know . These are not conducive to teaching mental models. Either one could in theory lead to development of a mental model, but due to a lack of student motivation and ability, they don't. Students use study techniques that learn conscious knowledge, such as rehearsal and cramming. The exam then tests the students conscious knowledge. If you test students' conscious knowledge immediately after they have studied, there will be an illusion of learning. But if you test again later, even that illusion will be gone.

And so our schools fail, and our children do not learn.