Class conditional probability distributions of the two top ranking input features.

A. Combined distance-from-the-hairpin distribution for 3′ and 5′ miRNAs. Note that for 5′ miRNAs the distribution is shifted by approximately 22 nucleotides (average length of the mature miRNA) as the mature miRNA is located between the hairpin and the miRNA start position. This is not the case for the 3′ samples. Note that in both cases, the distribution of actual mature miRNAs is quite narrow indicating that mature miRNAs are located within a short distance from the hairpin. B. Distribution of the position-specific feature located 8 nucleotides prior to the start of the mature miRNA sample. Note that differences between positive and negative data are small, even for the top scoring position-specific feature, indicating that the two classes are hard to distinguish. All distributions are estimated over the training set.