Abstract
The behavior of the K1 rule estimating the number of factors: A study with simulated data. Althoug the theoretical drawbacks of the rule, the Kaiser-Guttman criteria for determining the number of factors is still widely used, when working in Common Factor Analysis. In order to assess the behavior of the rule, the number of factors, the proportion of variables to factors and the proportion of sample size to the number of variables in the sample are controlled in a simulation study. The bias in the estimation of the number of factors and the communalities are gauged. This criteria shows a regular overestimation of the communality. Still, it only fails to determine the right number of factors when the relative sample size is small.