13 Is PCA unstable under multicollinearity? 10 Partial Correlation Interpretation 6 "matrix is not positive definite" - even when highly correlated variables are removed 6 How to generate a large full-rank random correlation matrix with some strong correlations present? 6 How to "regress out" some variables?

### Reputation (1,500)

 +10 Test which test to use: (Student-) T-test or (Mann-whitney) U-test +10 Is PCA followed by a rotation (such as varimax) still PCA? +10 Factor expressed as standardised variable in factor analysis +10 How to "regress out" some variables?

### Questions (15)

 9 What is PCA doing with autocorrelated data? 5 Estimating specific variance for items in factor analysis - how to achieve the theoretical maximum? 4 How is the proof that the Quartimax/Varimax-rotation converges? 4 Significance/confidence intervals for PCA or factor loadings - how can such be defined? 3 Significance test of whether participants have more friends of the same sex

### Tags (63)

 45 pca × 23 13 r × 9 21 factor-analysis × 15 13 multicollinearity 18 correlation × 6 11 interpretation × 3 16 regression × 7 9 spss × 7 14 partial-correlation × 2 9 exploratory-data-analysis × 4

### Bookmarks (10)

 510 Relationship between SVD and PCA. How to use SVD to perform PCA? 128 Free statistical textbooks 26 What exactly is called "principal component" in PCA? 14 What are the assumptions of factor analysis? 12 Factor rotation methods (varimax, oblimin, etc.) - what do the names mean and what do the methods do?