Fig. 4From: Video-based observer rated sleepiness versus self-reported subjective sleepiness in real road drivingBoxplots of the confidence in each rating grouped by video clip. On each box, the central mark is the median, the edges of the box are the 25th and 75th percentiles, and the whiskers extend to q3 + 1.5(q3 – q1) and q1 – 1.5(q3 – q1), where q1 and q3 are the 25th and 75th percentiles, respectively. Outliers plotted individuallyBack to article page