It isn't clear to me whether Mplus bases its parallel analysis on eigenvalues from EFA or PCA. My reading of the literature is that it is best to use PCA eigenvalues when using parallel analysis to make decisions about the number of factors to extract (even when one plans to use EFA when extracting and interpreting factors).
I'd be grateful for any clarification that folks can provide. Thanks! Skyler
Margarita posted on Sunday, February 15, 2015 - 4:02 pm
Dear Dr. Muthen,
Unfortunately I do not have the new version of MPlus, and so I have to conduct a parallel analysis using the SPSS syntax proposed by O'Connor.
I was wondering if you know whether it is preferable to use Principal Components Eigenvalues or FA eigenvalues to make decisions as to how many factors to extract when my plan is to use EFA afterwards for factor interpretation?
A couple questions. I've read that parallel analysis programs produce data sets with normally distributed random numbers. (1) I wonder if eigenvalues generated by these data sets can be meaningfully compared to observed data with high levels of skewness or kurtosis? If not, is there a way to produce random data sets that might approximate the structure of the observed data? (2) With nonnormal data, I wonder if the MAP test may be more appropriate? Is it appropriate to use the MAP test in an EFA context? Does Mplus provide a way of doing this?
Thanks for the quick reply. I am referring to Velicer's (1976) Minimum Average Partial (MAP) Test. I found a paper by O'Connor (2000) that provides SPSS and SAS syntax for both a parallel analysis and Velicer's MAP test. I was hoping there might also be a means for doing this in Mplus.
The problem with parallel analysis for categorical variables is due to using poly choric correlations. With 5-point Likert scales you can typically treat the variables as continuous and the problem isn't there.
Paula Vagos posted on Tuesday, April 14, 2015 - 3:30 am
Hello, I am trying to do a parallel analysis in mplus and keep getting this error message:
*** ERROR in ANALYSIS command Unknown option: PARALLEL
My syntax is: VARIABLE: NAMES ARE U1-U6; CATEGORICAL ARE U1-U6; ANALYSIS: TYPE = EFA 1 3; ROTATION IS CF-VARIMAX; PARALLEL = 50; PLOT: TYPE = PLOT3;
Could you please help me?
Paula Vagos posted on Tuesday, April 14, 2015 - 5:20 am
on a follow-up note, taking out the "categorical are u1-u6" part of the syntax did not fix the problem...