Methodology:
To assess the rigor of the curriculum at some of the nation’s top colleges, we first whittled an initial list of nearly 2,000 accredited four-year colleges and found the top 200 most selective according to the percentage of applicants admitted and the median SAT/ACT score for accepted students. The most selective schools were then ranked using data from College Prowler on student assessment of workload manageability (out of 10 points) and the student-to-faculty ratio according to the National Center for Education Statistics. (Smaller class size and greater professor oversight are proxies for tougher classes.) For the final ranking, the degree of selectivity, workload score and faculty ratio were each weighted a third.
In other words, these are the colleges where accepted students find the workload most difficult when normalized by the aptitude of the student body.