Higher-order factors are not commonly discussed in the literature, but it is likely that you will run across discussion of this topic at some point. We included this chapter because we feel that it is not discussed enough in research methods, and too much in the content literature.

Higher-order factors are tricky. They are not difficult to empirically evaluate once you figure out how to perform the analyses. The trickier issue is deciding whether there truly is a higher-order factor or whether the original analysis should have specified a single-factor structure and, finally, whether there is a meaningful difference between the two. We remain convinced that these exploratory techniques are fun, but relatively low in value without confirmatory techniques to evaluate the competing hypotheses in a more rigorous manner, and replication in independent samples. Also, if you are committed to performing this type of analysis within an EFA framework, Thompson (2004) has described in detail a more modern methodology for presenting this information.