Nodes are categories (L2), with colours indicating the theme (L1) and size being proportional to the average effectiveness of the intervention. Arrows from nodes i to j denote that those countries which have already implemented intervention i tend to implement intervention j later in time. Nodes are positioned vertically according to their average time of implementation (measured relative to the day where that country reached 30 confirmed cases), and horizontally according to their L1 theme. The stacked histogram on the right shows the number of implemented NPIs per time period (epidemic age) and theme (colour). v.p., vulnerable populations; c.e., certain establishments; quarantine f., quarantine facilities.