The Magical Number Seven, Plus or Minus Two: Some Limits on Our
Capacity for Processing Information
by George A. Miller
originally published in The Psychological Review, 1956, vol. 63.
The details of Millers '7 plus or minus 2' have already been
explained, so her is just a breif summary of his paper:
> First, the span of absolute judgment and the span of immediate memory
> impose severe limitations on the amount of information that we are able
> to receive, process, and remember. By organizing the stimulus input
> simultaneously into several dimensions and successively into a sequence
> or chunks, we manage to break (or at least stretch) this informational
Miller is saying that often there is far too much stimuli to
process and store in our memories, therefore we have to
organise the information by 'chunking' it together to make
better use of our ressoures. For example: If we think of a
cat, dog and hourse separately it can take more time and
effort than if we were to group the objects together i.e.
attribute the name 'animals' to them, which can then be
extended to represent any 4 legged creature.
> Second, the process of recoding is a very important one in human
> psychology and deserves much more explicit attention than it has
> received. In particular, the kind of linguistic recoding that people do
> seems to me to be the very lifeblood of the thought processes. Recoding
> procedures are a constant concern to clinicians, social psychologists,
> linguists, and anthropologists and yet, probably because recoding is
> less accessible to experimental manipulation than nonsense syllables or
> T mazes, the traditional experimental psychologist has contributed
> little or nothing to their analysis. Nevertheless, experimental
> techniques can be used, methods of recoding can be specified,
> behavioral indicants can be found. And I anticipate that we will find a
> very orderly set of relations describing what now seems an uncharted
> wilderness of individual differences.
A question arising from this is: How do we actually know
that VII means seven, in the same way that 'est' in French
means 'is' in English? Perhaps we do recode words into
English forms to process them, or otherwise maybe we have
different systems which process the variety of different
inputs e.g. a separate system for understanding musical
notes, morse code, and Roman numerals etc:?
Traditional experimental psychologists have found this hard
> Third, the concepts and measures provided by the theory of information
> provide a quantitative way of getting at some of these questions. The
> theory provides us with a yardstick for calibrating our stimulus
> materials and for measuring the performance of our subjects. In the
> interests of communication I have suppressed the technical details of
> information measurement and have tried to express the ideas in more
> familiar terms; I hope this paraphrase will not lead you to think they
> are not useful in research. Informational concepts have already proved
> valuable in the study of discrimination and of language; they promise a
> great deal in the study of learning and memory; and it has even been
> proposed that they can be useful in the study of concept formation. A
> lot of questions that seemed fruitless twenty or thirty years ago may
> now be worth another look. In fact, I feel that my story here must stop
> just as it begins to get really interesting.
Miller explains that the theory of information i.e.
experiments about 'Absolute judgement' allows us to
quantitatively show that we organise stimuli input and recode
information, and therefore can enhance and expand the amount
of information we are able to process.
> And finally, what about the magical number seven? What about the seven
> wonders of the world, the seven seas, the seven deadly sins, the seven
> daughters of Atlas in the Pleiades, the seven ages of man, the seven
> levels of hell, the seven primary colors, the seven notes of the
> musical scale, and the seven days of the week? What about the
> seven-point rating scale, the seven categories for absolute judgment,
> the seven objects in the span of attention, and the seven digits in the
> span of immediate memory? For the present I propose to withhold
> judgment. Perhaps there is something deep and profound behind all these
sevens, something just calling out for us to discover it. But I suspect
> that it is only a pernicious, Pythagorean coincidence.
Basically in this last paragraph Miller has suggested that
'7' has been an important figure throughout history, by
identifying that many issues i.e. the days of the week and
the deadly sins, occur in groups of 7's. He does highlight
that this maybe coincidental, but also leaves it open for
enquiry, as to whether there is an underlying reason for why
these things happen in 7's.
Perhaps it is linked, some what, to Millers '7 plus or minus
2' idea, that individuals only have the capacity to store
roughly 7 peices of information into their brains at a given
Well there you go thats the end of Miller (for now anyway!!)
See you all later,
This archive was generated by hypermail 2b30 : Tue Feb 13 2001 - 16:24:19 GMT