2008-02-10

Thinking in AI [0]: Why I don't need to know how to read EEG plots?

by Forrest Sheng Bao http://fsbao.net

Recently I wanna write a computer program that can diagnose a neural disease automatically from EEG data. Since I have no idea on diagnosis of this disease, those medical guys couldn't understand how I can "teach" a computer to some stuff without knowing how to it by myself.

So I gave them another example. I know nothing about botany, but Stephen Wu and I did build a program that can classify 32 plants. I explained to them that I just need to extract some features by signal processing techniques and "feed" them into a classifier, which is a mathematical transformation in essential. The the output of the transformation can tell me of which class the sample is.

They just couldn't understand the mechanism I explained to them. It looked like that I was discussing building a time machine.

Then I tried much easier way, I said we wanna find a mapping from the space spanned from feature vectors to a space of classes. Different classifiers (linear classifiers, ANN, SVM, integral transformation, etc.) are just different mappings. They varies on identity, speed, anti-noise ability, etc. You can just consider you have a lot of equations and you wanna find a solution. That's why I don't need to know any medical knowledge about diagnosis of this disease.

Well, it was still useless.

Besides this, I was always asked what Answer Set Programming is. It seems this time I am talking about building time machine again. Since I don't know how to solve Sudoku or many other puzzles, again, they couldn't understand why I can "teach" computer to do something without knowing how to it myself. I told them that I just need to tell the computer rules to generate solutions and criteria to eliminate wrong solutions, then the computer can figure out possible solutions by logical reasoning.

So now I am tried and I just wanna tell everyone can't understand my answers "Yes, I am building a time machine". It is as difficult as telling Indians in 1800s what space shuttle is. But I am a graduate student rather than a magician.

Since I am working on a project using pattern recognition and machine learning stuffs, I wanna make my professors know what I am doing - I am not playing video games at the lab. I plan to write down the techniques I know in this fields so I can check them when need to review them.

Ok, so I will discuss some basic ideas of linear classifiers next time.

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