Case-Based Reasoning Meets Learning by Doing

Goal-Based Scenarios:
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what the student might be thinking before he tastes his first beer and what would you predict that he
might think afterwards? These are very important questions for understanding EFK because knowledge is
only built upon prior knowledge.
The novice beer drinker could only have had one of two basic expectations. Since expectations come
from prior generalizations, we can only expect what we already have experienced. We have to have a
basis of comparison, and this comes from the prior experience that we have chosen as the best
expectation we can muster at the time. One might guess, for example, that this student would expect that
either beer tasted like soda, the thing it most resembles physically in the experience of a student, or it that
it tastes like some other alcoholic experience, such as wine drunk at a religious ceremony.
Some of the expectations that such a student might have would be quite reasonable. For example, he
might expect a liquid, for example, perhaps a non-poisonous, possibly slightly nourishing liquid,
probably a refreshing-on-a-hot-day kind of liquid. When I drank my first beer I remember being surprised
that it was bitter and wasn't sweet. What kind of criticism is it of beer to say that it isn't sweet? All
alcohol had been sweet before in my experience, so I expected sweet.
Every time we experience an expectation failure, we need to explain it so that it doesn't keep happening.
You can't go through your life always expecting there to be a parking lot on the corner of Fourth and
Maple. The day they start construction on a new office building on that corner, you must decide whether
this is temporary, like a carnival - maybe it will go away - and if it isn't, you begin to update your
expectations. No elaborate explanation is needed; in fact, we can explain it simply by saying to ourselves
that, yes, buildings do tend to get built where parking lots once were. But when they tear down a
beautiful old house to make way for a parking lot, a slightly more elaborate explanation must be
constructed, one that talks about the insensitivity of our times, perhaps, or maybe one about the money
needed to repair a grand old structure is just too much for anyone. But when expectations fail horribly,
when beer just doesn't taste anything like Coca-Cola, we have no explanations that are satisfactory. What
can you say? Beer just isn't Coke, and it isn't sweet wine. When this happens, we create a new category.
Once that is done, we are on our way to becoming an expert. The next time someone serves us a beer, we
can announce proudly that Miller just doesn't have the flavor of Budweiser. In fact, pronouncements like
that, made by amateurs after having had only two beers in their life, are usually quite accurate. You
remember your first beer and can easily distinguish the taste of the second from the first. After having
drunk hundreds of beers of many different sorts, it becomes harder and harder to distinguish one from the
other. You just have too much information. Unless, of course, you are paying attention, careful attention.
You have to care about what you are going to learn in order to learn anything at all.
Now imagine such a new expert beer drinker, tasting his first glass of champagne. He should expect
something beer-like. Champagne even looks like beer. Now suppose that the champagne drinker likes
champagne a great deal and drinks a lot of it, getting drunk and then later getting sick. What can the
student learn from this experience? One serious problem in learning to make day-to-day decisions is
understanding the results. Deciding which generalization to make, and thus which new expectation to
generate, when one is dealing in a complex environment, requires knowing more than you actually can
know on your own.
Suppose that we go to eat in a fine restaurant that serves Thai food. You have never eaten Thai food
before, you like the meal, but the next day you are sick. Should you avoid Thai food in the future or just
that restaurant or just squid, which you ate there for the first time? Or should you never go out to eat with
the people who took you to that restaurant? In real life, we have no easy answers to such questions. In
science, we can run an experiment and control the variables. You can eat at another Thai restaurant, you
can go back to the same one and avoid the squid, and you can also go out to another restaurant that is not
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