Accuracy achieved by PIntron, Exogean and ASPic at various levels. The boxplot presents the distribution of specificity and sensitivity achieved by the three tools at the exon, intron, transcript and nucleotide levels. The vertical edges of the boxes represent the first quartile, the median and the third quartiles (from left to right). The cross is the average. The vertical dashed lines represent an estimate of the 95% confidence interval of the median. The circles are all the outliers with respect to such confidence interval.