Last semester I sat down with one of my professors and talked through my interests in the psychological sciences. After I’d described what I was interested in, he told to give PSY-351 – Computational Modeling.
I’ve been to a couple classes now and I’m coming to better terms with what exactly a computation model is and isn’t. To be a computational model, you need not only a “what,” but also a “why.”
Take, for example, collaborative filtering that I worked on this summer. This is a statistical model. There’s nothing in it about why people like things, only the assumption that people tend to like similar things, so by looking at bunches of things that people like, we can pick out trends.
A computational model is actually something like the semiotic model I was playing around with which not only describes a method for determining what people like but does so by positing a structure for why they like those things.
Why is a computational model desirable? Well, consider physics. We could have a model that tells us how fast things fall out of the sky. It could get the rate of 9.8m/s2 and describe motion well. That is a useful model. Having a model of gravity and universal attraction gives us a “why” things fall and in doing so allows us to predict things about falling objects on other planets and orbits and all sorts of things.
Computational models, as opposed to statistical models or empirical curve-fitting models, because they provide a theoretical handle on to why the process takes place can be tested much more rigorously and ultimately, if proven reliable, may well provide predictions into areas where observation is currently impossible.
To date all that we have been discussing are models of object categorization, but our final project is to implement a computational model from a field related to our research and implement it.
I’m in a slightly difficult position in that the models that are most closely related to the research grant supporting my studies (interfaces for soldiers using robots searching for IEDs) would likely be computer vision and I don’t particularly want to learn those in depth. I’m going to go meet though with the professor and hopefully we’ll work something out. Maybe I’ll end up doing something related to preference modeling.