Sensitivity and precision of CRAC predictions by category for human simulated data. (A) Absolute numbers of true and false positives reported by CRAC. These figures are the number of distinct events, say SNVs, reported by CRAC, not the number of reads containing the same SNV. False positives represent a small fraction of its output, thereby indicating a high level of precision. (B) and (C) For each category, the figure shows the proportion of events found by CRAC for the 75 nt and 200 nt datasets. The blue bars are the true positives, while the red bars on top are the false positives. The height of a blue bar gives CRAC's sensitivity, and the relative height of the red part of the bar gives the precision. For the two read lengths, for all categories the sensitivity increases with longer reads, while the precision in each category varies only a little. SNV: single nucleotide variant