Lots a great opinions. I'll add my own.
There is nothing wrong with the traditional methods of teaching and learning. They have worked for ages and the world has steadily moved forward. If you want to make some minor argument about the horrific state of the world...feel free, but all I'm saying is that the methodology of the past has proven itself effective.
As to PBL...I have a little training in it since I was a teacher and PBL is really a pretty old concept that any decent teacher training program or school training program is teaching as an option. I have used the method to some degree in various settings, and it does work. Students do retain information better and often learn concepts in far greater detail when the students are motivated, but the disadvantage is that it takes longer to get the same amount of information across to students and in fully integrated PBL, students can miss the mark. It's very simple for a group of students to begin to work and by the end, if the lesson plan was supposed to engrain objectives A,B,C,D, and E into them, The students have learned A phenomenally, B and E just as well as if you'd just told them in a 20 minute lecture, and totally forgot to think about C and D. The same can easily be said of traditional methods, but at least with traditional methods the students can look back and see what the objectives were...some forms of PBL never allow the actual objectives of the lesson to become transparant.
Another issue is that studies have shown PBL isn't equally effective for all forms of subject matter and in all cases. Of course you can find any number of studies to contradict what I just said, and you can also find a lot that confirm what I just said...but the fact of the matter is that as subject matter changes, PBL cannot be expected to remain the same and retain the exact same results. For a field like dentistry that has a lot of science, aesthetics, interpersonal communication, business, etc associated with its education, it can be a little simplistic to say, PBL works for everything just fine and just as well and is the singularly best method to teach all of it, from pathology and dental materials to small business economics and biochemistry.
Finally, I can't understand why PBL is referred to so much like it is singular entity that is the same everywhere. The PBL I saw at USC is a very different, somewhat ornately structured form that I have never used or seen other schools use. PBL is pretty unstandardized. It has a general conception that every school and every professor twists, perverts, restructures, rethinks, and rewrites to fit whatever they believe will work best. PBL at Harvard is probably quite different than PBL in a classroom at Stanford, or San Diego State, or Michigan, or a high school classroom, or USC, or whereever you go. What student A experienced in classroom G is not always what student M experienced in Classroom N on the other side of the ocean. Unfortunately, PBL set up in a particular way is something that needs to personally be experienced to understand if it is gonna work, and it won't always work for you even if at first it does or if for one subject it did.
There is my 2 cents
