Boxplot of PDQ h metrics (block1_h, block2_h, block3_h, mean_h,
geomean_h, and the pooled overall_h extension), handling the same log
transformations as plot.score_mcq_output(). A caption marks overall_h
as a pooled beezdiscounting extension: pooling the three blocks presumes a
common h across reward amounts.
Usage
# S3 method for class 'score_pdq_output'
plot(x, ..., xlab = "Metric", alpha = 0.3)
