PREACHING AND TEACHING
Joseph Trenaman found that listening to more and more material in a lecture seemed to interfere with learning from the earlier lecturing.
A class listening to 15 minutes of lecture remembered 41% of what was presented; those listening to 30 minutes remembered 23% of the material presented in the first 15 minutes; those listening to 45 minutes remembered only 20% of the material presented in the first 15 minutes--and I can see that some of you are displaying a glazed look already, understandably.