I observed that Rotation failed to converge in 25 iterations, (Convergence = .007) when i performed Factor Analysis using SPSS. Why is it so and can i increase the number of iteration?
Hi. some more information need to be known such as number of factors used to run the PCA, whether the analysis done under the fixed factor and so on. Thanks
Hello Olufemi,
The convergence criterion in SPSS is, like any other choice, arbitrary. You may certainly adjust the number of iterations for a rotation. Here's an example:
FACTOR
/VARIABLES v1 v2 v3 v4 v5
/MISSING LISTWISE
/ANALYSIS v1 v2 v3 v4 v5
/PRINT INITIAL EXTRACTION ROTATION
/CRITERIA FACTORS(2) ITERATE(25)
/EXTRACTION PAF
/CRITERIA ITERATE(60)
/ROTATION VARIMAX
/METHOD=CORRELATION.
The first instance of "ITERATE" gives the maximum number of iterations for the factor extraction method chosen. The default is 25.
The second instance of "ITERATE" gives the maximum number of iterations for the rotation method chosen. Note that I set that at 60 for this example.
Good luck with your work.
As David Morse's answer indicates, there is an option within SPSS to increase the number of iterations. His example assumes you are using Principal Axis Factoring with an orthogonal rotation, is that correct in your case?
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