Date:         Tue, 1 Apr 2003 20:25:23 +0100
Reply-To:     Jeremy Miles <jnvm1@york.ac.uk>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Jeremy Miles <jnvm1@york.ac.uk>
Subject:      Re: Negative Coeeficient Alphas
Comments: To: Spencer Baker <srbaker54@cox.net>
In-Reply-To:  <004b01c2f883$c4438a00$6401a8c0@Primary>
Content-Type: text/plain; charset="us-ascii"; format=flowed

Negative alphas are theoretically impossible, as alpha is a proportion of
variance.  This most commonly occurs when you have failed to reverse some
items that should have been reversed.

JM



At 14:20 01/04/2003 -0500, Spencer Baker wrote:
>I am using an instrument that has lower level scales and an overall scale.
>It was originally created for adults and I am using it with a much younger
>population to compare. I am receiving some low and negative coefficient
>alphas at the lower level scales but the overall scales are in the .70s.
>
>Is there an article that discusses this phenomenon? It is a small sample
>(N=151) so far.
>
>TIA
>
>Spencer