Quelle(s) stratégie(s) adopter pour sélectionner des cas dans une recherche qualitative ? Illustration à partir d’une recherche comparative sur les changements dans la structure du pouvoir exécutif en Equateur
What strategies should be adopted to select cases in a qualitative research ? Illustration from a comparative study on the changes in the structure of the executive branch in Ecuador. In a qualitative research design – particularly a comparative one - case selection is undoubtedly one of the most critical issues. The literature proposes a series of individual selection strategies, but in practice, researchers use them in combination. This discrepancy between theory and practice motivated us to propose a sequential combination of qualitative techniques for case selection that meet four objectives: to achieve variation in outcome, to respect the diversity of the set, to highlight the different degrees of a continuum, and to highlight the substantial importance of each case. The process was carried out in two stages: first, a pre-selection made directly by the researcher, and second the selection itself, carried out with the participation of experts by means of the Delphi method. The empirical basis of the proposal is the design of a comparative research on changes in the structure of executive power in Ecuador during the three presidential terms of Rafael Correa Delgado (2007–2009, 2009–2013, 2013–2017).