I disagree as well. I know for a fact, and you can check with WPD, that the surronding areas of Clark University are not safe. The school does a great job keeping their students aware and offering security to help students. But it is not a safe area. For additional proof check out this archived article from worcester magazine
http://www.worcestermag.com/archives/2003/05-22-03/Cover.htm, the majority of the dirty dozen as they call them are located in Main South. Here's an article that specifically discusses Clark University's problems, and that of the immediate vicinity.
http://www.worcestermag.com/archives/2004/04-01-04/lead_continued.shtml. Here's one on Castle Park in Main South
http://www.worcestermag.com/archives/2004/07-08-04/index.shtml . These are just some examples. I feel confident telling you for a fact that it is not a safe neighborhood, these articles illustrate some of the reasons why. For whatever reasons others on this board are trying to say otherwise, but I encourage you to call the Worcester Police and ask them for recent crime information in that area. I know that what you will find is above average crime vs. the city as a whole. If you want to use the internet, the Worcester Police has a really great website where you can find stats on crime in the area.
http://www.ci.worcester.ma.us/cau/ Although we all call Clark University "Main South" in the WPD maps its actually Zones C4,C5 which is considered central worcester. I hope that helps. Now you can make an educated decision on the neighborhood safety.