Abstract
For Jari-Erik Nurmi, the practice of model-making in psychology is a complex process operating on different levels simultaneously. At first sight, his account seems to reflect Suppes' (1962) notion of a hierarchy of models: from low-level data models to high-level theoretical models, where at each level the model represents "structure" at a different degree of abstraction, and the levels are connected through structural isomorphism.1In this commentary, I want to complement and perhaps somewhat redirect Nurmi's analysis of his own modeling efforts—away from the idea of an interconnected hierarchy of isomorphic structures, towards more autonomous roles of the models at different levels, each with its own ..