Case-Based Reasoning Meets Learning by Doing

Goal-Based Scenarios:
The word process here sheds little light on these phenomena in the same way that "skill" shed little light
on what it was that we wanted people to know how to do. As with "skill" the word "process" can
encompass too much. There are many phenomena that can be called processes. There are political
processes, economic processes, scientific processes, and so on. What these ideas have in common is that
they refer to complex sets of forces that come into play that require more of their participants than a
simple knowledge of how to execute certain procedures. The phenomena they represent are complex and
often not given to clear procedures that can be guaranteed to work. There is one way to send e-mail and
program the VCR. There are known solutions to braking a car, riding a bike, or making toast. But for
what we have been labeling processes there are often no good answers or many good answers. What
answers there are are not executable procedures but rules of them, general strategies to try that may or
may not work under the particular circumstances that have arisen. For this reason, it might be better to
describe the substance of what we want people to learn about these phenomena as participation
strategies.
Thus, we can restate what is learned in a goal based scenario as micro-scripts, cases, and participation
strategies in various processes that are contained within the scenario. An ideal goal-based scenario would
involve many people participating as part of a team, a complex environment in which to work, and a need
to report the results. Such a scenario would cause participants to have to develop strategies for getting
along with other team members, reasoning about the complex domain, and communicating the results.
Learning by doing, when one is talking about processes, means inventing for oneself strategies that work
within the processes that one is involved in. When we asked what was learned in learning by doing earlier
we recognized that the same mental structures we had always used were active here as well and that our
old idea of scripts and packages of scripts was entirely relevant to learning by doing. In effect, learning
by doing modifies existing memory structures at the lowest level described in Schank (1982).
Now we must ask where participation strategies for processes fit into this scheme. The answer is again to
be found in Schank (1982). This becomes clear when one considers what a participation strategy actually
looks like. Let's consider a few. Some good ones for human relations might be:
if you want someone to like you, ask for their help
if you are in charge of someone, be firm but treat them as an equal
Some good ones for reasoning might be:
in order to attack a new problem, try to see it is an instance of an old problem
in order to find a solution, hypothesize a world in which the current problem wouldn't exist
Some good ones for communication might be:
never say everything you know in one speech
always write in an easy to read, unpretentious style
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One thing that should be obvious here is that these rules are most certainly not always right. Their
opposites could also be right under certain circumstances. Further, they are accumulated by experience,
by actually trying to engage in processes. Thus, they have all the characteristics of what were referred to
as thematic organization packets (TOPs) in Schank (1982) and have been referred to as indices in several
subsequent books (Schank, 1986, and Schank, 1991 in particular). These strategies are developed from
particular cases. Cases provide data for generating abstractions, store exception episodes to warn of
problems with existing knowledge structures, and provide a starting point for future comparisons
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1/22/2010