Monday, May 12, 2008

Working memory down from 5-9 to 3-4

7 plus and minus 2

The famous George Miller paper ‘The Magic Number 7 Plus and Minus Two’ has turned out to be rather optimistic. In practice, research from the University of Missouri has shown that working memory struggles beyond three or four items. Try remembering the letters IFCMBAIBI.

Working memory is what we use most of the time to function and is critical in problem solving and maths as we need to hold several items in the mind for comparison and manipulation. We know that we have as little as three or four working registers so if we store IFCMBAIBI as IBM-CIA-FBI, it’s easy. This article appeared in April’s Proceedings of the National Academy of Sciences.

This has important ramifications in learning as it lowers the bar on the possibility of cognitive overload. The lesson is that fewer items need to be presented at any one time and that chunking becomes very important.

1 comment:

Blogger In Middle-earth said...

Kia Ora Donald,

I was one of Dr Jacob Bronowski’s fans way back in the 60’s. I used to watch him on BBC TV giving the most inspiring lectures.

One lecture I remember vividly was when he demonstrated how a series of 20 playing cards, selected at random from a pack of 52, could be remembered in the exact order that they were drawn. What’s more, using his technique he was able to recall what the nth card was when requested.

The technique was well known and practiced by memory-men of the time. It simply required memorising a familiar series of objects in an exact order so that each was also identifiable from its position in the list. A list of visualisable objects like: cup, comb, wineglass, pencil etc up to the twentieth object had to be committed to memory.

When the cards were drawn (or any array of 20 visible objects appeared) the observer allocated each as it occurred according to the its associated item in the memorised list.

In terms of cognitive overload, where does this feat sit on the scale?

Ka kite
from Middle-earth