[Bug]: PCA results do not match SPSS

[TarandeepKang]

JASP Version

0.18.3

Commit ID

No response

JASP Module

Factor

What analysis are you seeing the problem on?

PCA

What OS are you seeing the problem on?

Windows 11

Bug Description

This forum post: https://forum.cogsci.nl/discussion/9294/kaiser-normalization-for-oblimin-rotation#latest

Inspired me to dig around in PCA for a little while. I find that PCA results differ between SPSS and JASP. By the look of the documentation, we are using the psych for PCA. And I believe therein lies the difference. The documentation doesn't mention whether kaiser normalisation is applied in Jasp so I therefore assume not? And this may therefore explain why the results are different between it and SPSS? This would certainly fit with the reasoning behind the kaiser function in the psych package?

https://rdrr.io/cran/psych/man/kaiser.html

If it isn't already, might be a good idea to add this functionality as a checkbox at least, if not to make it the default?

Expected Behaviour

See above. Results should not differ with SPSS, unless Kaiser normalisation is not recommended?

Steps to Reproduce

I have just been using the Spearman data from the data library with varimax and oblimin rotation and some example data I found online. I then compare with SPSS bank2.zip (attached).

Log (if any)

No response

Final Checklist

• [ ] I have included a screenshot showcasing the issue, if possible.
• [X] I have included a JASP file (zipped) or data file that causes the crash/bug, if applicable.
• [X] I have accurately described the bug, and steps to reproduce it.