This is a multi-part message in MIME format. ------=_NextPart_000_0000_01C5E3F0.C8B2E2B0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable From: Steven R Brown Date: Mon Nov 07 15:52:59 CST 2005 T Q-METHOD@LISTSERV.KENT.EDU Subject: Re.: Use of SPSS I must disagree with some of the presumed advantages of SPSS advanced by David Goldstein. At 05:32 PM 11/6/2005 -0500, David M. Goldsteinwrote: Some of the pluses of using SPSS: It provides some help with the issue of how many factors to extract.=20 Steve,=20 Do you decide how many factors are present only after rotation=20 Particularly in connection with judgmental rotations, the nature of the factors and which to retain is a judgment that emerges as the = factoranalyst interacts with the data. A priori criteria, such as Cattell's scree test or eigenvalues greater than 1.00, are onlyassociated with the statistical properties of the data.It provides somedifferent ways of rotating. I have found that the Equimax method keeps onyielding results which are consistent with judgemental rotation.This has to be mainly accidental.
I understand your point.. However, I keep finding that the Equimax method of rotation keeps on producing the same results as when I use judegmental rotation. The Lipset data is usually used to illustrate the advantages of judgmental rotation. The Equimax rotation produces the same result. Is it possible that when a person is doing judgmental = rotation that the person is doing something similar to what Equimax is doing? In a sense, Equimax rotation could me a model of what is happening with judgmental rotation.
That is, there can be nosystematic connection between equimax or any other automatic rotationprocedure (which responds only to the statistical topography of the data) and judgmental rotation, which mainly responds to content, or totheoretical considerations. The statistical configuration can ofcourse influence the analyst's decision making, but there are too manyother considerations (of which equimax, varimax, and other rotations are oblivious) that will also play a role.
One can obtainfactor scores just like with the other programs. True enough, but PCQ and PQMethod provide analyses of factor scores(based on standard error formulas) that are missing in SPSS, and probablySAS (with which I am not familiar). Steve, I don undertand this statement. Can you explain it a little more. One can analyze the items for patterns over time. I use the k-means cluster analysis program. This is probably similar to the repertory grid people. I'm sure that SPSS can do this, but looking at individual items outside of the context of the overall response that gives them meaning (if thisis in fact what is being done) is to violate the gestalt principle. Steve, The k-means cluster analysis results in clusters of items. In the way that I am doing it, each cluster consists of items which have a similar pattern over the therapy sessions. So there is a getalt involved. One can createnew variables from the factors which result. For example, I created aQ-sort which reflected the degree of conflict between the differentself-images which resulted. The Conflict Q-Sort can then be entered intothe analysis with the other Q-sorts.
I'm not sure what this implies. How exactly was the new Q sortcreated? Steve, This analysis can be seen in the case study which I recently published in Clinical Case Studies. For each item, I looked at the largest difference in factor scores (expressed as a z-score) among the three factors. The factors were interpreted to reflect self-images of the person. For each item, if the largest difference was zero, this shows that the different self-images are the same. If the largest difference was maximal, this would show conflict between the self-images. The z-score different scorses were rank ordered from smallest to largest and this became a Q-sort that reflected conflict amont the self-images.Incidentally, I'm not saying that any of the above statistical strategies(e.g., analyzing items over time) isn't useful for some purpose oranother, but it's equally important to be mindful of the principles fromwhich these practices depart.
[此贴子已经被作者于2005-12-22 11:07:40编辑过]
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