It would be nice to know if the professors graded low were familiar with english as a first or second language. I had some asian teachers that when they spoke I could hardly understand their english. Thank god I could read their chaulk board equations otherwise I would have dropped out of engineering school.

Wow! Some professors get low marks and some get high marks at the same schools! Look, the only way to determine whether a professor is any good is to go to www.ratemyprofessors.com and check with a big grain of salt. Check out the textbook reviews on amazon.com and you will see a love/hate relationship with what are regarded as the best textbooks available. So it is the same with professors. Some students hate em, some students love em. All that matters is the schools job placement office success. If all the graduates get jobs then it's a good school. If none of the graduates get job offers then the school is no good whatsoever. For example if you graduate last in your class at Harvard law school then you still get a six figure starting salary. That's how good the school is. At schools that are not as good, you need to be in the top 10% of your class just to get a job offer. The marketplace determines if the school is any good.

Why not just present all of the data?