I am opposed to doing much traditional "lecturing" in most classroom contexts that I find myself in, which are typically classes with less than 35 students. For one, I think lecturing encourages passivity: students just sit back and typically just let ideas wash over them, at best. Second, I think it discourages doing the reading, if a lecture substitutes for that, as it often does: if the lecture will sum up the basic ideas and arguments, why bother reading about them in the readings? (And somewhere I have gotten the idea that there is research to show that most people learn best from reading, although I now retain that belief probably on the basis of wishful thinking!). I prefer spending our time doing learning activities that students could not do on their own.
Fortunately, I am not alone in having these kinds of thoughts about lectures. Here are some recent articles on lecturing:
Lecturing vs. Teaching Problem-Solving Skills
Breathing Life Into the Lecture Hall
To Lecture or Not to Lecture, an Age-Old Question
A guru here seems to Eric Mazur from Harvard's physics department.
I wonder if people have any thoughts on this issue, know of other relevant discussion, etc.