Accuracy of single- versus multiple-organism searches. A. Precision, averaged across all GenMAPP pathways, is plotted against different levels of recall. The results obtained for individual PMT nodes are shown as separate lines with single-organism results shown as dashed lines and multiple-organism node results shown as solid lines. Average precisions for A. thaliana, H. pylori, Eukaryote, and Cellular nodes are not shown because each had fewer than 10 pathways with the minimum number of query genes. B. The highest precision level at 50% recall rate for all single-organism nodes versus multiple-organism nodes. Each dot corresponds to the precision obtained by the search-engine for a single pathway. Solid line indicates y = x, the line of equal performance; multiple-organism searches resulted in higher precision for pathways above the line and a lower precision for pathways below the line. Dashed lines indicate a high precision rate of 20%.