Normalising sequence lengths using the relative duration of episodes: an application to doctoral trajectories in Germany

To address significant variation of sequence lengths of doctoral trajectories, we propose sequence normalisation using the relative duration of episodes. We employ episode data from a panel study of doctorate holders in Germany where doctoral trajectories are measured in single months and differ in length up to several years. Utilising normalised sequences instead of absolute sequences, we are better able to identify typical trajectories. The graphical presentation of the cluster solutions more accurately depicts the underlying processes. Furthermore, it offers the possibility to define reference sequences without a fixed length. Normalising sequences instead of distances thus proves an easily implementable method to compare sequences of different lengths when the identification of patterns is a priority.