The percentages were not part of his original pyramid, they are just made up. And there is no research verifying the 'order' of the parts of the pyramid, either.
From Wikipedia: "Dale's "Cone of Experience," which he intended to provide an intuitive model of the concreteness of various kinds of audio-visual media, has been widely misrepresented. Often referred to as the "Cone of Learning," it purports to inform viewers of how much people remember based on how they encounter information. However, Dale included no numbers and did not base his cone on scientific research, and he also warned readers not to take the cone too seriously."
Here are some other articles debunking the cone and percentages: http://www.willatworklearning.com/2006/05/people_remember.ht... http://www.brainfriendlytrainer.com/theory/dale%E2%80%99s-co... http://www.asee.org/documents/sections/pacific-southwest/200...
That said, there is plenty of support for the general idea that the more participatory and applied our learning, the better. For example http://www.vcu.edu/cte/workshops/teaching_learning/2009_reso...
The given source is the National Training Laboratories in Bethel, Maine. However, they happily admit that they're unsure how it came to have figures.
"Yes, we believe it to be accurate - but no, we no any longer have - nor can we find - the original research that supports the numbers. We get many inquiries every month about this - and many, many people have searched for the original research and have come up empty handed.”
