Figure 1

Experiment annotations, annotation values, and measurements. A set of experiment annotations (left upper box) is assessed describing an experimental context, here a microarray study of pancreas cancer samples. Each experiment annotation (e. g. tumor type) can take several annotation values (right upper box). Each of these annotation values (e. g. serous cystadenoma) annotates a set of microarray measurements. Each measurement is affiliated to exactly one annotation value per experiment annotation. In this manner, each experiment annotation represents a possible grouping of the measurements, with each experiment annotation value representing a distinct group. If this grouping corresponds to the transcription patterns observed, the experiment annotation is relevant for the experimental context under study.