Introduction
Microarray classification involves assigning groups of genes with common expression patterns into biologically or clinically relevant classes. For example, a researcher may ask whether knowledge about expression patterns for a set of genes can be used to tell whether an individual has a particular cancer. The overall goal is to be able to establish a set of criteria that, when given an unknown sample or microarray, can be used to classify the sample in a biologically meaningful way. Clustering – the sorting of genes studied in a microarray into groups with similar expression patterns – is often a useful step prior to classification.