Q scores for contigs of different size. The number of questionable clones identified by FPC rises with the size of the contig. Very large contigs tend to have a disproportionate number of Q's, suggesting improper assembly of repetitive sequences. The line represents a least squares fit of y = 0.252x (r2 = 0.54).
Katagiri et al. BMC Genomics 2005 6:89 doi:10.1186/1471-2164-6-89