On Wed, 28 Feb 2001 12:08:55 +0100, Nicolas Sander
<[EMAIL PROTECTED]> wrote:
> How is Cronbach's alpha affected by the sample size apart from questions
> related to generalizability issues?
- apart from generalizability, "not at all."
>
> Ifind it hard to trace down the mathmatics related to this question
> clearly, and wether there migt be a trade off between N of Items and N
> of sujects (i.e. compensating for lack of subjects by high number of
> items).
I don't know what you mean by 'trade-off.' I have trouble trying to
imagine just what it is, that you are trying to trace down.
But, NO.
Once you assume some variances are equal, Alpha can be seen
as a fairly simple function of the number of items and the average
correlation -- more items, higher alpha. The average correlation has
a tiny bias by N, but that's typically, safely ignored.
--
Rich Ulrich, [EMAIL PROTECTED]
http://www.pitt.edu/~wpilib/index.html
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