8/24/19: Updated with Spring and Summer I '19 data.

Professor rankings are based on the lower bounds of the 95% Wilson score confidence intervals for the recommendation rate of every professor that taught a given course in the past two-three years (Fall '16 through Summer I '19 at the moment).

The threshold for time commitment warnings is one standard deviation from the mean commitment for all courses.

The expected grade warning is given when the expected grade (based on student surveys) is farther than 0.4 points from the actual average.