Edgar Dale was a US educationist and professor of educations at Ohio State University. In 1946 he developed his most famous model, the cone of learning.
Since then it has been quoted frequently, far and wide as the definitive evidence for how we retain information when delivered in various styles and mediums and has informed how to design training courses in specific ways.
Hear are the most popular figures in a typical illustration of the whole model:
There are some variations on the theme, quoted with the same level of authority as the ones above.
This one is typical:
Audio Visual: 20%
Discussion group: 50%
Practice by doing: 75%
Teaching others or immediate application of learning: 90%
Source: Kurt Lewin - National Training Laboratories
The only problems are these:
It was called the “Cone of Experience” not “The Cone of Learning”
Every single percentage associated with the various levels is wrong.
When Dale first published his cone there were no numbers associated with the model at all. There was no research used to generate it and Dale even warned his readers not to take the model too literally.
Indeed in his last iteration of the model in 1969 (published six years before he died) it still did not contain any numbers.
Many people, including Chi, Wiman and Meierhenry are credited (blamed??) for first publishing the percentages attached to Dale’s original cone but investigations undertaken by the blog “Myths and Worse”, indicate that most likely, the bogus percentages were first published by an employee of Mobil Oil Company in 1967, writing in the magazine Film and Audio-Visual Communications.
In 2006 Michael Molenda, a professor at Indiana University, tried to track down the origination of the bogus numbers. His efforts have uncovered some evidence that the numbers may have been developed as early as the 1940′s by Paul John Phillips who worked at University of Texas at Austin and who developed training classes for the petroleum industry. During World War Two Phillips taught Visual Aids at the U. S. Army’s Ordnance School at the Aberdeen (Maryland) Proving Grounds, where the numbers have also appeared and where they may have been developed.
This is interesting as it indicates that the numbers came first, then Dale’s model and then someone bunged the two together.
Of one thing we can be certain:
While Dale’s cone may give us some useful indicators as to the best way to generate retention, his was not a scientific research study and he made no claims what-so-ever about the percentages.
As we have already seen in previous posts, there is plenty of dis-information still swilling around in our industry. Trouble is, debunking it is all too easy. I am fundamentally a lazy person and I am having no trouble at all finding the myths amongst our facts. And if I can do it, so can those we need to build credibility with.
So our call to action today is simple:
If you quote Dale’s Cone of learning in any of your materials you should immediately re-name it the Cone of Experience (‘coz that’s what it was called) and remove those nasty percentages.
Sorry if this gives you more work to do. Just trying to help.
pine cone image by vickisnature