Brad DeLong wonders about the amazing endurance of classroom lectures as an institution. With the availability of other relevant technologies (books over many centuries, and the internets now), knowledge is available, basically, on tap. He asks:
Why not get everybody to buy the book, read the book, and then assemble in seminars to discuss the book?
Almost all of us can read faster than a lecturer can talk.
It is much easier to index and rewind a codex than a live audio stream before the age of mechanical reproduction.
"Yet, the Lecture Remains. Why?" Here are his four hypotheses:
Budget stringency: lectures are cheap for the university relative to seminars, and even if they are markedly less effective they do soak up students' time.
Alternative information channel: The ears are wired to the brain differently than the eyes, and there is value in not only reading something but also hearing something in producing the synaptic changes that we want to see happen in college.
A self-discipline device: if people have to show up at a certain place at a certain time to accomplish a task or be disciplined, they are more likely to do so. Lecture as a way of solving our self-command and self-control problems.
But why not then just have a study hall? Everyone reads the book, and the monitor circulates and answers quetions?
A sociological event: East African Plains Apes like to do things in groups that involve language -- that is just who we are -- and the lecture is just another example of this.
DeLong's question is about the relative merits of lectures vs. seminars. At the undergraduate level, there's nothing that can beat the experience of being introduced to an exciting new field -- gently, in a series of lectures -- by a great teacher. That still leaves us with another question: What about video lectures? Would 'live' classroom lectures survive when great lectures are freely available (see footnote)? For example, if you are taking an undergrad course in physics, what would you prefer: real lectures or video lectures from Yale or MIT? [Let's assume that the quality of live lectures is not too different from those others].
My own preference is clear: live lectures. Largely because of the interactive nature of the 'live' classroom. And because of the presence of others around me with shared interests.
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Footnote: Check out Sramana Mitra's model that uses such video lectures for taking high quality college education to large numbers of Indian youth. The motivation for this model is the acute faculty shortage in our institutions at all levels.