We all have clickers so that the lecture can be interactive (see picture) - the professor can put up a multiple choice question, and we all put in our responses, and then it shows us what percentage of students chose each answer. It can be used for attendance as well as just a gauge for who knows what (are we high-tech or what?!).
Some lecturers put audience response questions throughout their lecture. While I certainly have no problem with that, it drives me bonkers when professors actually get upset with us for picking the wrong answer. "Come on guys, I just went over this 10 minutes ago!" Sorry that some of us don't automatically recall every detail you tell us after hearing it once - if we did, there would be no need to study, and med school would be a breeze!
Same thing with a case discussion we had the other day on liver diseases. The four hours of liver lectures had been given the morning before, and that afternoon there had been a mandatory three-hour class for Physician's Core on how to do an abdominal exam. So, our apologies for not being able to learn everything about the liver in one evening - again, if we could do that, med school would be easy-peasy!
But during the group discussion we had about a fake patient with liver disease, the professor leading the group was so upset when we didn't have all the answers. "Guys, your test is in a week, you're making me very nervous right now." A week is a liiiiifetime for studying in med school (especially when we have a test every other week...). Like I mentioned in Whipple I, most people I know don't get a good grasp on the information until the weekend before the exam. Cut us some slack, and give us time to study the information before you assume we're never going to learn it!