This rings true from my experience, but I had never heard of this man. I looked him up. He's from the University of Chicago - the same as my father! The articles I read said that the percentages or retention attributed to the different types of learning were not Dale's, and that this was not what his research was about at all. He was interested in media in education. The titles of his published works seem to support that. You refer to a 1969 study, but you don't cite it. Can you post that study so we can read for ourselves. I can find no reference to it. Thank you.