The "forgetting curve" and Tony Buzan

Anyone who has been on a course about learning will probably have seen a graph similar this.



It is called a forgetting curve and shows how quickly we forget something we have learned. Just enter "forgetting curve" into Google Images for many examples. The curve was first established by Herman Ebbinghaus experimenting on himself using nonsense syllables. However, it seems like the general shape of the curve is true for a large range of different subject matter and conditions - and that fits in with our everyday experience. The key points are:

• you forget most soon after learning
  
• the curve flattens out so that the stuff you do retain you forget more slowly
• you can change the shape of the curve with revision and recall

All that is not controversial and I think anyone who has had to learn or teach would have taken the forgetting curve for granted.

There is a slighty different shaped forgetting curve in use:


which suggests that we can actually remember more a short period (e.g. 10 minutes) after learning something than we can remember immediately afterwards. I got this from Tony Buzan books such as "Use your head" and "Speed Memory" and I have faithfully reproduced it in my courses. It has some interested consequences for an instructor. For example, it might be more effective to finish a presentation, take a short break, and then summarise - rather than the traditional order of summarise and then take a break.

Yesterday I noticed that this "Tony Buzan" shape is not mentioned in any of my more academic books on memory. So I thought I would track down the original research on which it is based. Several frustrated hours later I gave up. The Buzan books do not give academic references - they just use phrases such as "studies show". Google threw up several places where this shape of curve was used - some quite respectable but they all seemed to come back to Buzan. I tried using various academic databases to search the voluminous literature on memory and forgetting - but they all came back to the Ebbinghaus shape not the Buzan shape.

I don't know that it makes a lot of difference for teaching or learning in practice. You still need to review regularly to avoid forgetting. But it frustrates me - especially as I have believed and repeated the Buzan line for nearly 30 years now.

So, if anyone reads this and knows of evidence for the Buzan curve or knows there is no such evidence - I would really like to hear from them.

Meanwhile I will treat is slightly differently when it comes up on my course.

What use is Kolb?

The Big Question at Learning Circuits on the use of PowerPoint included a reference to "some new research " which was actually a newspaper article about some research. I tracked down the original papers which were interesting about PowerPoint, but included this paper
"Why Minimal Guidance During Instruction Does Not Work: An Analysis of the Failure of Constructivist, Discovery, Problem-Based, Experiential, and Inquiry-Based Teaching"

It slaughters a range of sacred cows including David Kolb's learning cycle and learning styles inventory. Here is a quote from the paper:

"Attempts to validate experiential learning and learning styles (Kolb, 1971, 1984, 1999) appear not to have been completely successful. Iliff (1994), for example, reported in “a
meta-analysis of 101 quantitative LSI studies culled from 275 dissertations and 624 articles that were qualitative, theoretical, and quantitative studies of ELT and the Kolb
Learning Style Inventory” (Kolb, Boyatzis, & Mainemelis, 2001, p. 20) correlations classified as low (< .5) and effect sizes that were weak (.2) to medium (.5). He concluded that the magnitude of these statistics is not sufficient to meet standards of predictive validity to support the use of the measures or the experiential methods for training at work. Similarly, Ruble and Stout (1993), citing a number of studies from 1980 through 1991, concluded that the Kolb Learning Style Inventory (KLSI-1976; Kolb, 1976) has low test–retest reliability, that there is little or no correlation between factors that should correlate with the classification of learning styles, and that it does not enjoy a general acceptance of its usefulness, particularly for research purposes."

I sometimes include the Kolb learning cycle in my courses. Does this mean I should throw it out? I don't think so. It is a matter of asking the right question.

If you ask - does Kolb describe how people learn?

Then the answer has to be "no". There isn't the evidence.

But if you ask - does Kolb describe a way people learn?

Then the answer is almost trivially "yes"

And the really important question becomes "is it useful?". It is the difference between a psychological law and a pragmatic tool for thinking about training. I find Kolb really useful, provided I treat it as a tool and not as a prescription. I generally interpret the experience stage very broadly e.g. it might include the presentation of information or experience the delegates have had before they come on a class. Then it reminds me to allow for reflection, which might be drawing out common factors from the experience in discussion, conceptualisation, bringing it together into some general lessons, and experimentation - OK try it yourselves.

It is not the only way of structuring a class - but it is often a good one.

Using PowerPoint creates a context

My first post is inspired by this month's Big Question at Learning Circuits on the use of PowerPoint. This seems to come up regularly and many people have already made excellent points about it being only a tool and what matters is how you use it. There is also loads of stuff on what makes for good PowerPoint. I particularly liked Karl Kapp's examples.

What strikes me is that using PowerPoint creates a context.

Look at the picture above. The room is darkened. I am willing to bet there is no view of the outside - either its a room with no windows ore all curtains or blinds have been drawn. Everyone faces in the same direction. There is probably a background hum from the projector. The short sighted put on glasses and (unless they have variable focus) they can no longer easily see their notes. It also sets a social context. Most audiences will have listened to countless PowerPoint management, finance, sales, etc presentations. They expect to be passive , somewhat bored, and not to have to work hard.

All of this applies whatever is on the slides. So if you want your audience to be active, excited and hard working then you are going to have to work that bit harder to make it happen.