Correlations between the MCV coefficient ρ_Pearson and MIR variability properties. (a)–(d) ρ_Pearson vs. intrinsic variability amplitude σ_m in the W1 and W2 bands for NLSy1s and BLSy1s. (e)–(f) ρ_Pearson vs. mean MIR color ﹩\left\langle {\rm{W}}1-{\rm{W}}2\right\rangle ﹩. (g)–(h) ρ_Pearson vs. the host-contamination proxy ﹩r-\left\langle {\rm{W}}1\right\rangle ﹩. Purple and orange points denote RQ NLSy1s and RQ BLSy1s, respectively; red diamonds indicate RL counterparts. Dashed lines represent linear regression fits for the RQ populations.