Figure 3. Confusability matrix.

Rows: rater-chosen expressions. Columns: intended expressions. Diagonal represents agreement between rater-chosen expressions and intended expressions, with warmer colors representing greater agreement (red = 100% agreement, blue = 0% agreement). Off-diagonal cells represent confusability of intended expression for an alternate expression, with warmer colors indicating greater confusability. Expressions identified as “none” could not be classified (i.e. they were ambiguous). The parent of this model provided written informed consent, as outlined in the PLOS consent form, for publication of their child’s photographs.