Re: Alpha and mean inter item correlation

Posted by Rich Ulrich on Oct 23, 2012; 9:31pm
URL: http://spssx-discussion.165.s1.nabble.com/Alpha-and-mean-inter-item-correlation-tp5715788p5715808.html

Yep, all you can see from a FA of 5 items is that, yes, these
seem to go together.  Too trivial.  Include some others that
*don't*.  And 3 items is too small for anything that is
preplanned. 

I usually like more than 5 items in a scale.  I like it,
especially, if my whole 69 items would be reduced to 3-5
subscales, or 10 at the most.  Is a factoring of 35 still
garbage?  23? 

Since you are a novice, I will mention:  Do these as CFA
(iterate on the communalities) and look at the Varimax
rotation - it is usually more sensible than the unrotated solution.

--
Rich Ulrich

> Date: Tue, 23 Oct 2012 14:11:20 -0700

> From: [hidden email]
> Subject: Re: Alpha and mean inter item correlation
> To: [hidden email]
>
> Hi Rich
> Thanks.
>
> I did a t test to see if there are any changes.
>
> I did a FA just to see whether d variables can go together before the t
> test. Initially I fed all 69 variables and the result was garbage. Didn't
> show anything coz of the large number of variables. A consultant suggested
> that I grouped the variables into themes. I did that, so there are about 3-5
> variables in a theme. I ran that in FA. I thought it make sense coz the
> results make sense with the cronbach alpha either .7 or below that.
>
> When I showed to my Sup, he said nope cannot b done that way coz i hAve
> grouped them. So I can't do a EFA. But the grouping was done using face
> validity. I am so confused.
>
> Another question, inter item correlation, ok I do stage 1, I can roughly
> look at the items tat might b correlated. So do I used these items to do a
> factor analysis? Is that d reason? Asked my Sup, no answer at all. Feeling
> frustrated especially for a novice and trudging to make sense as to why I am
> doing this.
>
> It did make sense for factor analysis but trying to make sense abt inter
> item correlation and after this, what should I do.
>
> Sorry still need help
> ...