Nanny Wermuth Mathematical Sciences Göteborg University Types of graphical Markov Models, illustrated with symmetric binary variables. Abstract A wealth of different types of graphical Markov models has been developed by now, with multivariate regression chains and their subclass of triangular systems being most suitable for modelling development in joint and single responses over time. Symmetric binary variables arise for instance when continuous variables are categorized into two groups with the cut-off value being the median. However, their attractiveness for demonstrating similarities and differences between simple models that are typical for different model classes stems from closed form representations, also after conditioning or marginalising.