39

All quantitative, probabilistic surveys rely on a sample frame. However, this sample frame is generally presented as a given even though its creation is a complex operation requiring methodological choices that are rarely objectivized. Within the framework of a survey of 14 socially and spatially diverse neighbourhoods, we created our own sample frames encompassing a total of 17,113 residences. This survey allowed us to open a black box, which concerns public statisticians as well as ethnographers who strive for representativity, and to identify the principle difficulties associated with this operation: i.e. gaining access to all houses under the dubious, or even hostile, eyes of the inhabitants; determining from the roadside or threshold what actually constitutes a residence, and creating a standardised coding system despite the diversity of residential contexts involved.