Main and interactive effects among and between AUs for positive and negative ratings.

Relative importance of the main effects and interactions among all AUs for positive and negative human-coder ratings. Relative importance (normalized partial dependence from the RF model) is a measure the SD in the outcome variable (i.e. positive or negative affect intensity) attributable to each AU while integrating over all other AUs, and it can be interpreted as how important a given AU is with respect to all other AUs. Note that partial dependence is not directional (see Fig 6 for directional effects). Visual depictions of the 5 most important AUs for predicting positive and negative ratings are shown on the graphs. Because there are 190 possible combinations of AUs for displaying interactive effects, we only show the top 20 here for brevity.