A while back, Mike Pulsifer pointed me to an article on Ars Technica: Study: class podcasts can lead to better grades. The article, and the research done by State University of New York, focus on whether using podcasts as an extra study resource for students can improve grades. I am a huge fan of podcasts. Over the past couple of years I have learned an immense amount by listening to podcasts – from language, to photography, to brain science, and design. On iTunes U anyone can access lectures from some of the best universities in the country by downloading and listening to podcasts of each lecture. This is a great way to acquire knowledge or to get further study for a class you're currently taking.
What I found even more interesting about this study was the method of teaching and study that wasn't as effective: handing out printed copies of the lecture slides to students. As the author of the article notes, passing out PowerPoint handouts has become "all the rage" in many lecture halls, within or outside the academic world. In fact, two of my previous science courses are designed around PowerPoint handouts – every slide of every lecture for the entire semester is included in a "Lecture Guide" that the students purchase at the beginning of the semester (sometimes in lieu of a textbook).
What's the problem with this?
PowerPoint slides are NOT notes. They should not function as notes. Not for the teacher and especially not for the student. Retention increases when exposure to information occurs across multiple modalities - listening to a lecture, reading a textbook, discussing a subject in a study group, etc. (You may be familiar with the idea of being a visual vs. kinisthetic vs. auditory learner.)
A printout of common lecture slides is not much different than the lecture - except that you probably aren't having them read to you by a Ph.D.
But repitition increases recall, right?
Yes, that is true, but do not forget that certain modalities of learning are less effective than others. As Dr. John Medina points out, "the brain sees words as tiny pictures. Reading creates a bottleneck." (Brain Rules, pg. 234)
This is just one more reason to do away with text on those lecture slides, replace them with images, and maybe even replace the handouts with a link to the podcast version of your next lecture.