PBL at Cornell is like this: On Monday you get in your small groups (about 10 students plus one physician preceptor) and you are given the beginning of a case. For example, you will all get a paper with information about a new patient to your office who is complaining of abdominal pain. Then you will spend the next hour and a half discussing this case. At the end of that time, you will all split up topics that you will present on Wednesday. You go home, look up your topic, research it, and make a short presentation with a 1-page handout. On Wednesday you will all present and then receive more parts to the case, like maybe some other lab values or physical exam findings. You will discuss again, then again choose more topics to research for Friday. You get the picture. Each week is a new case, and you discuss that one case for the whole week during your PBL time, which occurs Mon, Wed, Fri from 8-9:30am (for most courses).
That's PBL. You can read my opinion on this in my previous posts.
Small group sessions occur when you meet in your group of 10 students, but you aren't doing PBL. You might be going over histology, pathology, microbiology, any kind of problem sets that were assigned, etc. You might even go over cases. For example, when you are learning about pulmonary disease, you might have a small group session with a pulmonologist (each group will have its own attending). In this session, you will all read a paragraph about a case (maybe a patient with fever and cough) and then discuss the differential diagnosis, what tests you might order, and how to treat the problem. You will do 3 to 5 of these cases in an hour. It sounds very similar to PBL, doesn't it? The HUGE difference is that in these sessions, someone is leading them and ensuring that you don't go completely off track, as there is a time limit and you need to cover all of the cases. The pulmonologist, being an expert in the field, will quickly get you to the key information that you need to focus on. You cover a lot of useful information very quickly, and you remember it because you remember the cases. If you've read my earlier posts, you can see how different this is from PBL.