The Comparative Agendas Project brings together researchers who are developing systematic indicators of the attention given to political problems in their own national political systems. The main objective of the project is to build up a standardized taxonomy in order to compare activities linked to these problems over time and space. The construction and application of a reliable thematic classification, which covers the political agendas of many countries, is an arduous and complex task. However, it has considerable potential for the comparative study of policy. In this paper, we focus on the objectives, the challenges and the future of this new approach.