Figure 2
From: Improved base-calling and quality scores for 454 sequencing based on a Hurdle Poisson model
Distribution of quality scores by 454 native base-caller at HPLref 3 overcall. The empirical cumulative distribution functions of 454 quality scores assigned to bases associated with HPL 2, 3 and 4 in case of an overcall for sequences with reference HPLref 3. The distributions are nearly identical, implying that no insight is provided by the 454 quality scores about whether an undercall or an overcall is more likely, given that a base-calling error was made.