What is a tier one university?

There is no single ranking of universities, but the label "Tier I" is often applied in the context of research universities. The Center for Measuring University Performance produces an annual ranking of research universities (institutions with at least $20 million in federal research expenditures) measured across nine factors. The results are grouped according to universities ranking in the top 25 nationally on at least one factor, and then those ranking 26-50 on at least one factor. The top category (including 51 schools in 2007) are often collectively referred to as "Tier 1" research universities.