After cleaning up the results of the survey and adding the regional dummy variables, the database still contained 72 variables. Applying a data reduction technique may therefore help to reveal the relations between governance practices of port authorities in Europe and explain port governance diversity. Factor analysis is commonly applied to explore data sets with many variables, which are then summarised into a limited number of unobserved factors. Doing this, the analysis tries to keep the number of factors as low as possible while maintaining a maximum of the information, which is present in the original data. For each factor, the factor loadings indicate to which extent they are correlated with each variable. If the factor loadings of two variables show similarities, these variables are related. On the basis of the resulting pattern, factors are often labelled and accordingly, clusters of observations can be detected (Stevens, 2002).