A university should be a place where students can be exposed to new ideas, where they can engage freely in debate and discussion. But do college students really feel free to speak their minds on campus? Newly released College Free Speech Rankings show that, at most colleges, the answer is no.

RealClearEducation launched the College Free Speech Rankings, with an interactive website, so parents and students can see how schools they're interested in stack up.

The rankings are based on a survey of nearly 20,000 students at 55 schools across the country. The survey reveals some startling facts. Almost 20% of students say that using violence to stop an unwanted speech or event is in some cases acceptable. Among Ivy League students, 36% said that it was "always" or "sometimes" acceptable to shout down a speaker one doesn't like.

Self-censorship is also a major problem. Sixty percent of college students say they have kept quiet due to fear of how others would respond. Among conservative students, that number is 72%.