Figuring out factors: the use and misuse of factor analysis

Factor analysis is a technique which is designed to reveal whether or not the pattern of responses on a number of tests can be explained by a smaller number of underlying traits or factors. Similarly, it can be used to indicate whether or not the various items on a questionnaire can be grouped into a few clusters with each cluster reflecting a different construct. As with all multivariate statistical tests, it is quite powerful and can provide much information about the instruments being used. Similarly, there are many ways it can be abused and misinterpreted. This paper will explain the basics of factor analysis and provide some guidelines relating to how the results should be reported.