The Magical Number 7

The Magical Number 7, Plus or Minus 2 - Some Limitsthe result will be unreliable. Therefore it is essential to
to our Capacity for Processing Informationcarefully select those factors which have a bearing on
Having studied the behaviour of senior managementa problem.
one often observes that they don't like being inundatedSecondly, the chronic shortage of time. The formulation
with an abundance of detailed data and always try toof a Focus and the understanding of the CSF's of a
concentrate on the heart of the matter. This can becompany are based on these considerations. Inevitably
illustrated by the fact that when you ask a seniormany strategic decisions are based on a few selected
manager to name the Critical Success Factors of hisfactors while we understand that reality is much more
business he mostly comes up with 7 plus or minus 2complex. Montgomery commented that:
factors (5 to 9). For him these are the essential"A commander has got to be a very clear thinker: able
strategic indicators.to sort out the essentials from the mass of lesser
There are two reasons for this:factors, which have a bearing on every problem.
Firstly, the fact that most human beings can only relateMilitary problems are in essence simple, but the ability
7 plus or minus 2 variables at once. One could say thatto simplify; and to select from the mass of detail those
this is our mental span of control. When confrontedthings which are important is not always so easy"
with a larger variance, the quality of the judgmentsMontgomery believed that the ability to select the
made become unreliable. Many indications point at theessentials from lesser factors is crucial.One might
fact that humans possess a natural selectionconclude that the remark of Montgomery and the
mechanism which protects us from informationbehaviour of managers point at a natural human
overload. Many psychological tests reveal that when acharacteristic.
person has to interpret or relate more than 9 variables