This is a graduate school ranking based on a survey and fairly meaningless due to how it's done: Specialty rankings of doctoral science programs are based sole

This is a graduate school ranking based on a survey and fairly meaningless due to how it's done: Specialty rankings of doctoral science programs are based solely on nominations by department heads and directors of graduate studies at peer schools. These respondents ranked up to 10 programs in each area. Those with the most votes appear in the rankings tables. This biases the result towards top regional schools, whose peers rate them highly over well-known schools that are otherwise great, but have weaker CS programs than its best peers. Either way, this has no real relevance in terms of comparing the quality of those who complete their undergraduate programs. The selection effect dominates all other factors here and almost no school has separate admissions for computer science (not aware of any in fact other than CMU) which means to the extent most people rank them, it is roughly in order of the overall prestige of the undergraduate program in general. I mean University of Wisconsin - Madison is a great school, but on average, you won't find their graduates to be quite as good as Harvard or Yale grads.