Fig 5. Illustration for Algorithm 1.

Given a hierarchical clustering of samples that are annotated with Ontology terms (colored boxes, ancestry relations are shown with black lines), it detects enriched ontological categories on various levels of abstraction in each possible cluster: while analyzing the indicated cluster (black box, emphasized triangle), all present categories (and their ancestral categories) are characterized by their F-measure. E03 and especially E20 (parent of E02 and E03) are relatively specific for this cluster, as evidenced by a relatively high F-measure, whereas E01, E10 and E02 are mostly present outside the cluster, reflected by a small number of True Positives. Abbreviations: TP = True Positives, FP = False Positives, TN = True Negatives, FN = False Negatives.