There are many aspects which should be considered when evaluating a college/university, but a couple of statistics which I always feel are revealing are the Freshman Retention Rate (the percentage of students who return to an institution for the second year) and the Graduation Rate (the percentage of students who begin at a university and graduate, usually within four years, from that institution).
In my opinion, low percentages in these areas could be indications that things aren't functioning quite as they should be in the environment of that college/university. Institutions surely want to keep their students. Reputable institutions want their students to be happy and to succeed. Therefore, these institutions strive to provide a challenging academic program, while also providing a wide spectrum of extracurricular activities in which students can become involved. A variety of services are usually in place to help students who may be having difficulties academically, organizationally, psychologically, or socially, or otherwise adjusting to the demands of college life, so that a student can find his/her niche and have a successful college/university experience.
When I see low Freshman Retention Rates or low percentages of graduates, my first thought is: Why? Why do so many students not want to return to that particular institution for a second year? Why is the institution unable to support such a large number of their entering students through four or five years of study, seeing them through to a successful graduation?
Of course, there will always be students who made an inappropriate college/university choice to begin with or have to leave the institution for a variety of other personal reasons, but these isolated instances would not reveal a strong statistical trend. The Freshman Retention Rate and the Graduation Rate do, however, reveal statistical trends, which I feel are well worth considering when evaluating an institution.