European territorial policies increasingly refer to broad goals such as sustainability, well-being and cohesion. For their operationalization as political goals, there is a need to create indicators. But how can an indicator be meaningful in relation to a complex concept that is not well defined? If the creation of an indicator is primarily aimed at quantifying a concept and making it more operational, in the case of a contested concept (such as territorial cohesion), the process of building indicators also helps stabilize it, allowing a potential decontestation. A participatory constructivist approach – as used by the ESPON project Indicators for Territorial Cohesion (INTERCO) – is considered to be the most suitable for building indicators of contested concepts. While ensuring computability of the indicators, it allows more flexibility and reconciles the different meanings of the concept in order to stabilize it. Ultimately, the validity of indicators of contested concepts lies in pragmatic criteria: usability, usefulness and use.