Isagani Cruz linked to an article that asked, "Why are we so slow to change the way we teach?". In answer to his own question, the author gave three reasons: that change is harder than we think, that faculty underestimate the complexity in changing teaching, and that change is harder when attempted alone. The answers are kind of disappointing in their lack of specificity. It almost seems like it belongs to a self-help screed.
My own thesis is simpler. We find it hard to change the way we teach because the structures under which we are supposed to teach have not changed. As teachers, we are supposed to render a required number of contact hours with our students. That usually means three times a week, one hour each time, for 18 weeks. And this is to a class of 40 to 45 students. Think about it: you have one hour each session, and you have to deal with some forty students, each with varying degrees of capability and interest. How do you best make use of the time? Under that structure, the lecture becomes the safe and sensible approach.
Now what if we didn't have to meet the forty students all at once? What if we broke it down to meet with them, say, only ten at a time? Or what if we didn't have to fit a session into an hour? What if we could take as long as -- or as short as -- the time we needed to cover the topic? What if students didn't have to contend with so many courses in a semester? What if we didn't have to meet in a classroom at all? Changing these parameters opens up more possibilities for experimentation.
But the thing is: we're stuck with the model that we have. Why? For administrative reasons. It's easier to account for teacher time if you have them on a schedule. Easier, too, to account for student attendance. The one hour block makes it easier to schedule a class against the seven or eight other classes that the students have to take for the week. Meet outside the class? You'll need to have the students' guardians sign waivers for their participation. Only meet ten students at a time? But what about their required contact hours for the class? What about their attendance?
These reasons aren't entirely bad. What constrains a good teacher from experimentation is also what keeps a bad teacher from going delinguent in their class. But these structures don't offer a lot of freedom or incentive to change the way we teach.