The Idiographic Approach in Psychological Research. The Challenge of Overcoming Old Distinctions Without Risking to Homogenize.

In this paper I discuss the relevance of the single-case approach in psychological research. Based upon work by Hurtado-Parrado and López-López (Integrative Psychological and Behavioral Science, 2015), who outlined the possibility that Single-Case Methods (SCMs) could be a valid alternative to Null Hypothesis Significance Testing (NHST), I introduce the idiographic approach (Salvatore and Valsiner Theory & Psychology, 20(6), 817-833, 2010; Valsiner Cultural & Psychology, 20(2), 147-159, 2014; Salvatore Culture & Psychology, 20(4), 477-500, 2014) based on the logic of abductive generalization, rather than the logic of inductive generalization. I present the theoretical, epistemological and methodological assumptions that this approach proposes; in particular, I discuss the re-conceptualization of some now obsolete rigid opposition, the inconsistency of sample use in psychological research, the relationship between uniqueness and general, the relationship between theory and phenomena, and finally the validation process.