In this lecture we look at the principles of Qualitative Comparative Analysis (QCA) and how it works in an applied example of internet shutdowns during elections in Sub-Saharan Africa (Freyburg and Garbe 2018). QCA, a set-theoretic method developed by the American Sociologist Charles Ragin in the 1980s, helps scholars to study causal complexity among cases and identify necessary and/or sufficient combinations of conditions for an outcome. It can be a useful tool to combine systematic case comparison with in-depth analysis of individual cases in theory-evaluating or more exploratory, nested research designs. We discuss the assumptions underlying the method and the kinds of research questions it can (not) address. The results of a systematic review of empirical QCA studies illustrate good practices as well as areas where applied QCA still lags behind the considerable methodological innovations of recent years.