Since Robert Dahl coined the concept polyarchy, several attempts were made to develop indices that aim to measure citizens' political participation in a given polity. The present paper evaluates these efforts and shows that most of them equal the mentioned dimension to the extension of suffrage. This considerably 'thin' notion of participation has been criticized and was later enriched by other elements, most notably measures of voter turnout. With the growing number of works that catalogue and examine different processes of direct democracy, it is possible to further improve these indicators. This paper is an initial attempt to build an index that takes into consideration voter turnout and processes of direct democracy in an assessment of political participation.