Referendums give citizens a direct say over matters which would otherwise be decided by elected (or non-elected) representatives. Thus, as instruments of direct democracy, they may foster citizens' involvement and legitimise important decisions. In fact, referendums have been on the rise in Europe and elsewhere in the world in recent decades, and have become a recurrent feature of European politics. Since 1972, Europe has seen 54 referendums on EU matters, concerning membership, treaty ratification or specific policy issues (e.g. adoption of the euro); further referendums are to follow in 2016. At the same time, the degree to which EU countries make use of referendums differs significantly: while the majority of Member States have held one referendum on European integration, mostly relating to membership, a handful resort to referendums more frequently. Despite the increased interest in some states, referendums remain controversial. On the one hand, advocates of direct democracy stress that referendums can, inter alia, foster citizens' engagement and thereby improve legitimacy and governance. Critics, on the other hand, highlight the pitfalls of referendums. Especially in the aftermath of the French and Dutch rejection of the Constitutional Treaty in 2005, they suggest, interalia, that in referendums voters tend to answer questions other than those on the ballot paper. Some critics, more generally, question the suitability of a 'yes' or 'no' vote to decide on complex, multidimensional matters within the European setting. Looking at a sample of past EU referendums, the following pages provide an overview of these conflicting views, as expressed in (academic) commentary.