Two problems remain when analysing the ESPO database. First, a considerable amount of observations has missing values for one or more variables. Second, most variables are categorical in nature. Classical factor analysis,however, assumes continuous and normally distributed variables. Among others, Nisenbaum et al (2004) and Vanoutrive et al (2010) applied binary (categorical) factor analysis to get insight in questionnaires containing an extensive list of binary yes/no questions. The software employed in these studies, Mplus (Muthén and Muthén, 2006), allows one to carry out factor analyses with a mix of both continuous and categorical variables. Furthermore, this package can handle missing data without omitting valuable information, as is the case with standard list-wise or pair-wise deleting options in other software.