You’ve heard about CULPA. It’s been recommended by most of the many people who give you advice. But like Wikipedia, the underground listing has its flaws, and shouldn’t be your only source of information. Here’s Bwog academic advisor Owain Evans on how to get the most out of CULPA—as a source of entertainment, if nothing else.

Watch your sample size. If a professor has lots of well-written reviews that are all positive or all negative, then you’re safe assuming that she’s either really good or really bad. However, such unanimity (and consistently well-constructed reviews) is rare. Without it, be wary of drawing strong conclusions.

The Slacker Factor.
There are lots of malicious or misinformed reviews on the site, and it’s impossible to verify whether a review is accurate or not. Remember, lots of people in your classes don’t do the reading and are on the verge of falling asleep half the time. The reviews that such people write are unlikely to be of much use unless you also plan to avoid the reading and somnambulate to class. Also, many reviews are mere expressions of personal animus–even some of the well-written and detailed ones. The ‘user feedback’ feature can be useful in this regard, provided lots of people have voted on the accuracy of the review.

Ask the experts.
Make sure to check reviews of the more advanced classes a professor has taught, even if you’re thinking about an intro. Students in low-level classes are often ignorant of the subject being taught, leading to misinformed reviews. For example: “The prof kept going on about ‘proofs’ the whole time. He didn’t give us any calculations to do!” (This is actually what university math is like). Or, “The whole class was just about hair-splitting distinctions and we never got anywhere” (This is actually what philosophy is like). People who do advanced undergrad classes will tend to know the subject well enough to offer a balanced review.

Don’t bank on star power.
  Celebrity status does not a good professor make—be sure to check reviews even for people like Jeff Sachs, Brian Greene, Joseph Stiglitz, and PrezBo himself. Greene in particular has some cutting reviews, worth a look for their vicious virtuosity even if you’re not into physics.

My favorites: The cults of Jason Mohaghegh and Christia Mercer shouldn’t be missed. And my favorite thing on CULPA is a line from an Anders Stephenson review: “I asked him how much our midterm would count as compared to our papers. He states, ‘Oh, but it is all but a NARRATIVE in your academic life, sometimes it goes up, sometimes down.’”

— Mark Holden contributed to this article.