This chapter presents the design and implementation of our collective research program. The research combines quantitative analyses of public statistical surveys with in-depth qualitative case studies of households with relative economic stability. The statistical analyses help to compensate for the lack of recent sociological work on the working classes. They furthermore reveal that the internal structure of the working classes is relatively stratified into ‘upper’, ‘middle’, and ‘lower’ tiers, depending on the status of the occupation of each member of a couple and their respective professional positions. Lastly, statistical analysis allowed us to identify characteristics of the middle swathe and situate the studied households in the working-class space. The ethnographic aspect comes from the household case studies, which were designed to gather data on the economic, residential, familial, political, and professional dimensions composing working-class lifestyles. The resulting corpus makes it possible to identify consistencies in the lifestyle of middle-working-class people relative to other fractions, as well as certain principles of internal variation in social stabilisation processes, gender relations in the home, and forms of ‘Us’ / ‘Them’ relations.