Yet another introduction to Support Vector Machines. COMPJC CANCELLED DUE TO ILLNESS. TALK POSTPONED TILL NEXT WEEK. MAY 10, 2002
(Click on further readings above for references!)

In a problem of classifying points in a plane into two groups A and B, if the groups can be separated by a straight line, the support vector algorithm chooses the line such that the distance between that line and the points in each group closest to it is maximised. The points in each group closest to the dividing line are called support vectors. It turns out that this method involves calculating a scalar product. If the points are not linearly separable, a trick is to map them into a higher dimensional space in which they become linearly separable, and then apply the support vector algorithm. Unfortunately, calculating the scalar product in the higher dimensional space may be intractable because of the large number of dimensions. Fortunately, the higher dimensional scalar product is sometimes a function or "kernel" of the low dimensional scalar product. Using the kernel trick, the high dimensional scalar product can be calculated. There are arguments from statistical learning theory that the support vector algorithm tends to maximise the fit to the training data while not overfitting it, and hence will perform well on test data.

1:30pm -3:00pm, HSE 810.