This book aims to shed light behind the scenes of social science research into industrial relations and trade unionism. Which fields should be researched? Which actors should be given priority? How can different national contexts be compared? Is it possible to investigate industrial relations when they are not institutionalised? Is it possible to be both a scientist and an activist? And how can we understand the power relationships that develop in the field? This book details the current strategies trade unions use to address the following issues: the feminisation of trade unionism, the representation of precarious workers, the LGBT cause, the trade union issues at stake in the social and solidarity economy, and methods of providing material support for strikes. It also explores the professional universe of start-ups, bike delivery, and employers. Each of the twelve original contributions proposes methodological approaches based on ethnographic, statistical or archival research. They also provide an overview of current research and knowledge that will be useful to anyone wishing to learn how social sciences are investigated. Hence, this collective work contributes to renewing the field of industrial relations, decompartmentalising it and broadening its horizons.