Posing Your Mental Models

Yesterday I discussed the uses of games and other fun things in helping seniors gain expertise in using their computers. Underlying that theme is a thread that has run through all these columns: an instructor must understand the mental model the student has of computer usage. Things that have become obvious and “common sense” to the instructor fit comfortably into the mental model that the instructor has built up of the environment of computer usage. (Note I did not say “of computers.” The physical device is not the issue. How it interacts with the environment is the issue.) The mental model that a student brings to lessons is surely different from that of the instructor. Part of the education process is to help students adopt models with a high predictive capability of knowing what the computer will do in various situations. This is totally different from teaching how a computer works.

Consider what happens when a student first plays a game of solitaire. The mental model of separate items such as a mouse, its buttons, the images on the monitor, and the ominous sounds coming from hard disc activity begin to blend together into a pattern that becomes the model that when the mouse moves certain ways, the cursor correspondingly moves in certain predictable ways. Clicking does certain repeatable things. The student need not realize that the transfer equations for the mouse to the cursor are not linear. Consider the thing we call an accelerator on an automobile is not really an accelerator. If it were a true acceleration control, almost no one would be able to drive a car. In the same way, some pointing devices would be useless if the position of the device were linearly related to the position of the cursor; that is, if they truly pointed. The real situation is complex, but those complexities are largely irrelevant. The only important thing for a typical user is to have a well-worn mental model that, when the mind tells the arm to move a certain way, the cursor does a predictable thing, and the less thought it takes to make that prediction, the better.

Watch how a student progresses in using a word processor. A completely naive student brings to the table a rapidly changing mental model based loosely on whatever experience preceded the class. This experience most likely includes writing with a pencil and paper and a typewriter (remember we are thinking primarily of seniors here). The initial model predicts some things quite well. Hit the keys as if one is using a typewriter, and the proper letters appear on the screen. However, what happens to those letters when the screen fills up? What happens to them when the Delete key is pressed? What’s the difference between insert and typeover? What happens when you save a copy of a letter? Is it still in the machine if you print it out? Can you make multiple copies?

These types of questions that seem hopelessly trivial are often passed over as the student rapidly builds up a model of what is happening, and that evolving model gets more and more accurate. But here’s the rub. If the instructor is not asking questions, listening to answers, and generally being alert, the student can build up a model that is good in most situations - and fails miserably in others.

As a specific example, consider the difference between images and text. I’ve had several students who were mystified as to why they couldn’t scan a hard copy letter into their computer and then edit the resulting image in Word. “But my attorney did it with some legal papers…” “Yeah, most attorneys have expensive OCR software.” “What’s OCR and why do they need it?”

Mental model blockage is definitely not due to lack of smarts. It depends on what baggage you carry. Several years ago I attended the annual NAB convention in Las Vegas when digital video was being introduced. We saw a demonstration in which the presenter showed an original clip, and on an adjacent monitor showed the same thing. They looked identical. The presenter said the second video was a fourteenth generation duplicate. Ho hum, but the broadcast engineers next to me gasped. “I don’t believe it.” one said. The other just shook his unbelieving head. Until this point, I had been unimpressed. Digital is digital. You copy it as many times as you want. Maybe you need an error correction code: such is life. But these two highly trained, intelligent engineers grew up in an analog world where one had to plan carefully which generation of tape would be used because with each generation (tape or film), the image degraded. Try photocopying a letter through fourteen generations. The fourteenth generation of a standard analog videotape would be essentially useless. At that point I realized the presentation was boring to me because I was not the intended audience. The presentation was a mental-model-shifting device to analog engineers announcing business was now being done differently.

An effective instructor for seniors will be able to introduce this type of model shifting experience to students in a way that doesn’t drive them to disbelief like those engineers, but operates bit by bit and is fun along the way.