| Date: | Tue, 15 Feb 2005 10:01:48 +0100 |
| Reply-To: | Marta García-Granero
<biostatistics@terra.es> |
| Sender: | "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU> |
| From: | Marta García-Granero
<biostatistics@terra.es> |
| Organization: | Asesoría Bioestadística |
| Subject: | Re: help factor analysis |
| In-Reply-To: | <001101c512be$0ded2a20$b800a8c0@NOTEBOOK> |
| Content-Type: | text/plain; charset=ISO-8859-15 |
Hi
>> I have likert type data...trying to perfom factor analysis.
>> When I specify the number of factors I am getting the error
>> as shown below. Any syntax and pointers would greatly help.
>> What is happening is here? what am I doing wrong? what does
>> that say about the data? Any reasons why rotation is not
>> converging? I maybe wrong here but I want to use promax
>> results but what I would like to do first is to compare it
>> against Varimax and Oblimin rotations. I want to try to
>> extract different factors and try different rotations and and
>> report the results that makes the most sense but I am getting
>> this error in most cases.
First of all, have you checked the adequacy of the data for a factor
analysis?
You should take a look at Kaiser-Meyer-Olkin index (KMO) for an
overall check and the Measures of Sampling Adequacy (MSA) for each
variable.
FACTOR
/VARIABLES .....
/ANALYSIS ...
/PRINT EXTRACTION INITIAL KMO AIC <-------
...........
Interpretation of KMO:
KMO LE 0.5 Unacceptable
0.5 LT KMO LE 0.6 Low
0.6 LT KMO LE 0.7 Mediocre
0.7 LT KMO LE 0.8 Medium
0.8 LT KMO LE 0.9 Good
KMO LT 0.9 Very good
Measures of sampling adequacy can be scored similarly. Variables with
low MSA are poorly correlated to the rest of the variables, and should
be discarded for FA.
You will also obtain Bartlett test. A non significant value indicates
that the variables are not good for a factor anaysis at all.
HTH,
Marta mailto:biostatistics@terra.es
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