Lecture 3 Segment 5 covers the "Walking Man" approach to understanding computer-drawn ROC curves which consist of a discrete point for every unique test result in the sample. These ROC curves often have hundreds of overlapping points. Curve segments are often either completely vertical or completely horizontal.
Originally, I posted the entire Large Group Discussion from last year (10/6/2020), but that video was 91 minutes. I chopped off the introductory material and the student questions, shortening the video to about 34 minutes.