http://spssx-discussion.165.s1.nabble.com/questionnaire-design-dimensions-before-or-after-EFA-tp5715804p5715806.html
Not an SPSS question.
Of course you want to use forethought in making a scale.
It sounds to me like your real problem is that you have too
many chefs huddling over the stew -- Someone wants to toss
in *every* possible item in order to make sure that their
own spurned theory has some representation.
Let's say you have 200 candidates that make up your early
universe of items. Now you want to reduce that to 100, or
to 50 or less. You still have too many for a pilot study, even
after you drop the ambiguous ones.
So, what do you keep? Certainly, you want to represent the
dimensions that you *imagine* will be important. Depending
on the aim of the study, you may or may *not* want to keep
items for a dimension that someone else (or the literature)
says are important. Think of what you will write up -- What
is the basis of including items? What do you want to conclude?
How defensive will you have to be, for what sort of critics?
- You can't say that a dimension "does not exist" for your
eventual subjects if you had no items representing it.
--
Rich Ulrich
Date: Tue, 23 Oct 2012 13:06:36 -0700
From:
[hidden email]Subject: questionnaire design - dimensions before or after EFA?
To:
[hidden email]
Hello,
We have a misunderstanding regarding constructing a questionnaire. We have come up with a number of definitions and dimensions for a construct that we want to measure and now we must make items to represent the construct. Should we define the dimensions of the construct before conducting an exploratory analysis of the instrument or after it and try to see if exploratory factorial analysis finds the same dimensions that we referred to?
So basically, do we define the dimensions before making the items and then start making the items according to these pre-defined dimensions or just retain the dimensions after EFA?
Thank you and hope someone can help!
Andra Toader
E-mail: [hidden email]
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