The representativeness of social partners provides legitimacy for their various roles in industrial relations, whether through the vehicle of social dialogue, collective bargaining or involvement in government policymaking or implementation. This report compares the different ways in which the representativeness of social partners is defined at national, European and international levels. It shows that representativeness has various meanings across the 28 Member States and Norway, with most countries featuring a combination of legal conformity and mutual recognition. Based on information provided by national correspondents in the 28 EU Member States and Norway, the report analyses the concept of representativeness at national level by reviewing key elements such as electoral success, organisational strength in terms of membership, and the capacity to negotiate. The final section turns to the methodology used by Eurofound to assess representativeness since 1996 and raises the question as to whether this approach should be refined or modified after 10 years of application. An executive summary is also available - see Related content.