Expert advice is gaining importance in advanced-knowledge societies. The demand for scientific knowledge increases as political decision-makers look for answers to cope with the ever more complex challenges of a globalised world. At the same time, scientific evidence has become a strategic resource capable of justifying world-views and political positions. Against this background, the ‘global spread’ of think tanks seems to respond to this growing demand for scientific expertise. Defining what a think tank is, let alone what they do and if they are able to effectively shape political ideas, is still a controversial issue. This contribution outlines a conceptual framework for analysing the strategies of different types of think tanks in distinct institutional environments. Starting with classical typologies to distinguish between organisations, those which adhere to standards of scientific inquiry at one end of a continuum and ideologically biased institutes at the other, the analytical model takes into account distinct ‘points of intervention’ and systematically considers the respective institutional and ideological environment. The first dimension allows for distinguishing between distinct effects of political ideas: They can influence decision-making as concepts in the foreground or as underlying assumptions in the background of policy debates. At the cognitive level, they can function either as programmes (foreground), serving as policy prescriptions for the political elite necessary to formulate actual agendas, or as paradigms (background). Considering different ‘knowledge regimes’ permits to test the influence of respective institutional and normative settings and simultaneously assess the assumptions and convictions underlying these models and typologies.