The eigenvalue is a measure of how much of the common variance of the observed variables a factor explains. Each factor captures a certain amount of the overall variance in the observed variables, and the factors are always listed in order of how much variation they explain.

In every factor analysis, there are one fewer factors than there are variables.

their association with an underlying latent variable, the factor, which cannot easily be measured.įor example, people may respond similarly to questions about income, education, and occupation, which are all associated with the latent variable socioeconomic status. The key concept of factor analysis is that multiple observed variables have similar patterns of responses because they are all associated with a latent variable (i.e. It does this by using a large number of variables to esimate a few interpretable underlying factors. It allows researchers to investigate concepts they cannot measure directly.

Factor analysis is a useful tool for investigating variable relationships for complex concepts such as socioeconomic status, dietary patterns, or psychological scales.

Do factor analysis in spss 21