The type I error comparison results of the PRM, CWM, and PCR methods based on different sample sizes (150, 200, 250 and 300) and different minor allele frequencies (0.3, 0.4 and 0.5). The horizontal axis of each plot is the number of phenotypes q and the vertical axis is the type I error rate. The upper and middle dashed lines are 0.1 and 0.05, respectively.