Relative sensitivities/PPVs. A heat map showing the relative sensitivities and PPVs of the different prediction methods, or between prediction method and known structure. KH99′ and GG1, produce very similar structures which is not surprising, given they were found by changing one and two rules of KH99′ respectively. Otherwise, the methods have relative sensitivities/PPVs of approximately 0.5-0.6, which is as expected, given they are all designed to predict RNA secondary structure. However, it is clear that they are markedly distinct from KH99′ in their structure predictions.