Figure 1. Conceptual framework for the estimation of proportions of variance components in a mixed model.

The large grey circle symbolizes the variance in a response Y, the dark grey area on the top indicates the share explained by random effects and the coloured ellipses symbolize variance in covariates with intersections indicating jointly explained variances. partR2 calculates total R², part R² for individual predictors and sets of predictors as well as inclusive R². The package does not report partial R² and commonalities, although they could be calculated from the partR2 output.