This article on using lectures in physics perfectly enumerates several of the reasons for my distaste with lectures. Lectures are, by their nature, unengaging. There is no way to identify errors in your understanding during lecture. If you copy down everything, you do not have time to mentally engage the material. If you do not copy it down, you risk losing access to it. They do not promote learning (e.g. Academically Adrift by Arum & Roska). And so on.
The one that the article focuses on, and the one I think most critical, is that lectures are not based upon what the students do and do not know. They give everyone the same information, here is the critical point, without regard to their preconceptions and mistakes. Students often miss a certain foundational concept and then only build a superficial understanding or memorize for the test.
If a student only has lectures, homeworks, and tests, what would identify the deficiency? The lectures will not. Homework and tests both have the potential, but they are usually returned a week or more later after the student has forgotten what they were thinking while working the problem. Corrections can help, but are rarely required. The teacher usually reports the correct answers to the test in a lecture-style. Of course, the student can take the initiative and identify their errors, but that is the 10% that do not really need a teacher as the article notes. If a method’s main defense is that people can succeed despite it, the method is not good.
The technique of peer instruction described in the article (where the teacher submits a question to the class and students explain it to each other) is a band-aid. I agree, but I call the method a band-aid because it is not a fix. Slightly less of a bad thing and slightly more of a good thing is better; slightly less lecturing and slightly more interactive learning yields better outcomes. But this begs the questions: why do we use lectures at all?
I’m going to give a radical answer… The lectures of today are the remnants of a system being replaced. MOOCs, Wikipedia, and video games have demonstrated the tools. MOOCS are the first steps away from the old model with content permanently available to be watched at the students discretion, but I do not believe they will last. They make use of only a small bit of the potential. Imagine instead a system with an enormous bank of questions perfectly tailored to identify and correct a students exact errors in understanding, delivered like a video game where complexity is seamlessly increased and applications are built into the learning process.
Impossible, you say? I say it’s already happening.