item to total correlation?

deram

New Member
#1
I want to purify a scale, so I want to test for three things:

Doing a principal components EFA I assess:
a. Internal consistency. I will use Cronbachs alpha, right?

b. Item to total correlation. I don't know how to test for this.

c. Factor loadings.

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Then I believe I should drop items with low factor loadings and /or low item to total correlation.

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So my two questions are:
1. How do I test for item to total correlation in SPSS?
2. Why do most scale development articles test for three things (internal consistency, item to total, factor loadings) and then drop items based on only the factor loadings and item to total? Why do I then even do the internal consistency.

I know this may be a bit more in depth that usually here, but I hope someone can help me here. Thx.