What we know about knowing is wrong

TOURBUS Volume 12, Number 04

On with the show…


Dale’s Cone of Nonesense
Audience: Educators, Librarians, and Trainers

Since many Tourbus riders are also educators or librarians, I thought
I’d don my powder blue academic hood [see http://tinyurl.com/qjubv ]
and share with you some interesting academic research. There is a
concept in education called “Dale’s Cone of Experience” that states
that people generally remember:

10% of what they read
20% of what they hear
30% of what they see
50% of what they hear and see
70% of what they say or write
90% of what they as they do a thing

Often displayed graphically as a cone — see
http://teacherworld.com/dalescone.gif — Dale’s Cone has had a
profound impact on the way we teach both children and adults.

And it is a complete and total fraud.

No, really. Will Thalheimer at Work-Learning Research delved into
Dale’s Cone and discovered that:

1. While Edgar Dale indeed did indeed create a model of the
concreteness of various audio-visual material back in 1946,
the model contained no numbers and no research was conducted
to create the model. Dale’s Cone was just a hunch, albeit an
educated hunch, one that Dale warned shouldn’t be taken too

2. The percentages — ‘people generally remember 10% of what they
read’ and so on — were most likely added to Dale’s Cone by an
employee of the Mobil Oil company in the late 1960s. These
percentages have since been discredited.

You can see Thalheimer’s complete report online at


It’s an eye-opening read, especially if you’re an educator, librarian
or trainer. Let me also put in a plug for Thalheimer’s blog at


While I’ve known about Thalheimer’s investigation into Dale’s Cone
for a couple of years now, I’ve only recently discovered his blog.
It contains a collection of “research-based commentary on learning,
performance, and the industry thereof.”