Wednesday, September 23, 2009

Evolutionary Thinking

Any reader of my blog knows how I advertise the evolutionary approach to solving hard problems, but what does that mean? I have a prime example to trot out, something I came across on Reddit yesterday. The article is "The story of the Gömböc," which may not sound promising, but trust me. I dare not spoil this tale of discovery by condensing it into some trivial didactic--it's worth reading it its entirety. Commentary after the break.

This story has potential for all kinds of reflection on the practice of discovery. One could mention the noncognitives--trying every darned thing one could think of without giving up, for example, the willingness to be wrong and learn from it (accurate self-reflection). Or we could talk about the concept of critical thinking as iterating loops of analysis (testing a theory or evidence) versus creativity (finding theory or evidence). It's a marvelous example of critical thinking.

But I'd rather muse about what practical lessons can be drawn about the evolutionary approach. How can you actually do it? Suppose you have a tough problem at hand. How to assess higher order thinking skills in a discipline or how to get better evaluations of teaching effectiveness, or how to redesign general education? What evolutionary principles can potentially help find a solution? I have a few to suggest, and I'm sure you can think of your own (drop a comment if you do!).

First, maybe it's already been solved. If the problem has been around for a while, it's a good bet someone else has thought of it. I'm working on a research problem using a computational model for living things, and ran into a communications problem that looks like the sort of thing NASA would have to deal with. So I emailed yesterday to see if someone has already solved it. The internet is obviously good for that sort of thing. I don't know how many times I've wished I had some simple software tool, and two minutes later discovered that someone had created it and released it into public domain.

Well, if it hasn't been solved satisfactorily, what next? There is no magic evolutionary wand that makes the work go away. Think of picking over 10,000 stones on the beach looking for the right one. But the process can be described very easily.

First, you have to know what you want because you have to be able to identify it when you find it. That is, you don't need to know the form of the solution to your problem (otherwise you already have the answer), but you do need to be able to recognize it as a solution. You may not know off the top of your head what the prime factors of 1,010,299 are, but you can easily verify them once you're told (911 x 1109). This is the analytical part. In natural selection this is done by survival and reproduction. Critters that don't pass their genes on aren't solutions to the problem. For something fuzzy like identifying a good method of evaluating teaching, this is going to be hard to come to grips with. But setting out looking for a solution without knowing how to tell if you find one is a waste of time.

So you could, for example, decide that faculty confidence is the most important thing for teaching evaluations. Then the challenge would be to come up with some way to assess that--probably involving asking them what they thought of this or that method. If this sounds political, it's because it's a problem laced with politics.

With a tool for evolutionary fitness in hand, now you have to find a way to generate potential solutions. This is the creative part. My recent post on brainstorming quotes research saying this step is best not done in groups. But a group is good at weeding through the ideas. In the scenario I described (evaluating teaching), if faculty confidence is the key then having a test group to try out ideas against would be useful--to weed out ones they don't like. I think it's obvious that this weeding group should be different from the idea-production group; people are often too attached to their own ideas to be objective. So two groups: a creative one for idea production. They may or may not have to meet as a group. Then an analytical group for weeding out non-solutions. They have to be very clear as to what a solution looks like. Add a bit of salt and iterate and you have an evolutionary process.

In a nutshell, it sounds very simple. Generate lots of ideas and be ruthless about weeding them out according to your clearly-defined measure of success. Putting that into practice is complicated, however, and some level of formalization could help. Good leadership is a must.

Think about all the committee meetings you've sat in that wrestled with tough problems like these, but without a plan or clear notion of success, and almost certainly without a wall between idea production and idea deletion. How much time was wasted?

No system is perfect, and there are game-theory short circuits to the method I've described too. Without good leadership, the group responsible for judging success (killing bad ideas, keeping good ones) can have too great an influence on guiding where the investigation leads. The conversation can go like this (C = creative group, A = analytic (weeding) group):
C: Here's our ideas so far.
A: Nope. They all stink.
C: (Frustrated) Then what DO you want?
A: Well if you come back with this or that, we might be interested.
This becomes the equivalent of "teaching to the test," and subverts the process. On the other hand, constructive feedback is good:
C: What did you think of idea X?
A: It comes close--but the committee saw Y as a problem. Is it possible to create some variations?
The difference is subtle.

The evolutionary process for decision-making I've described above is theoretical and idealized. In practice it will always involve compromises. Deadlines will pressure incomplete solutions. There may not BE a solution, or it may be impractical. So treat this as a tool in your tool bag and not a panecea for all big problems. After all, natural selection got some things wrong too--I don't have the topological properties needed to stay upright when I fall asleep in long useless meetings, a useful trait indeed (gives me an idea for a comic strip).

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