The purpose of this paper is to show how social scientists have been measuring Quebec?s identity since the beginning of the 1960s. Various types of measurements were used in opinion polls, each partly reflecting the social and political context of the period. Since the end of the 1990s, the Moreno Question has been used as a measure of the dualistic Canadian reality and has contributed to reviving debates around the specificity of the Canadian national context as a multinational identity and a redefinition of ties between Qu?b?cois people and Canadians from other provinces. This redefinition of identities has taken place in the North American economic context, which has deeply transformed the continental identity of Qu?b?cois people.