How to do a factor analysis with the psych package

3 Item and scale analysis 5 3.1 Dimension reduction through factor analysis and cluster analysis . . . . . . 5 3.1.1 Minimum Residual Factor Analysis . . . . . . . . . . . . . . . . . . . 7 3.1.2 Principal Axis Factor Analysis . . . . . . . . . . . . . . . . . . . . . 8 3.1.3 Weighted Least Squares Factor Analysis . . . . . . . . . . . . . . . . 8 3.1.4 Principal Components analysis (PCA) . . . . . . . . . . . . . . . . . 14 3.1.5 Hierarchical and bi-factor solutions . . . . . . . . . . . . . . . . . . . 14 3.1.6 Item Cluster Analysis: iclust . . . . . . . . . . . . . . . . . . . . . . 18 3.2 Confidence intervals using bootstrapping techniques . . . . . . . . . . . . . 21 3.3 Comparing factor/component/cluster solutions . . . . . . . . . . . . . . . . 21 3.4 Determining the number of dimensions to extract. . . . . . . . . . . . . . . 27 3.4.1 Very Simple Structure . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.4.2 Parallel Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.5 Factor extension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30