Problem Based Learning

I wanted to discuss problem based learning, a concept that we have been covering in class over the past couple weeks. I feel that problem based learning is a very useful tool, which can enhance learning and be a very effective teaching method. With that being said, I feel that problem based learning must be used in conjuncture with other, more traditional forms of pedagogy, in order to be completely successful.
Take for example, the situation that Dr. Rockwell continued to use in class - medical students. Yes, problem based learning is an effective way of teaching students problem solving skills, and allow them to learn using potential real life situations, but without a general knowledge of the parts of the body, medical conditions, and remedies, the students will not have the sufficient background knowledge to solve these problems.
With that said, if students have the background knowledge, problem based learning is a very effective way to solve problems. The example used in tutorial - trying to increase the use of technology by McMaster professors, allowed me to see the effectiveness of problem based learning. This is an example of a situation where problem based learning is the most effective way to solve the problem, but I still maintain that in many courses, there is a certain degree of background knowledge that students must acquire in order for problem based learning to be an effective pedagogical tool.