The articles in this special issue make valuable contributions toward a scientific understanding of concepts that is broader than the traditional view that has focused on categorizing by individuals. I propose considering concepts for categorization as a special case of concepts. At their clearest, they can be referred to as "formal concepts," or…

This article makes a number of interconnected arguments. First, spatially and temporally distributed project teams constitute a new form of interprofessional work and, as a corollary, a new site for interprofessional learning. Second, researchers in cultural-historical activity theory have generated some concepts and methods, for example,…

A central dilemma in developmental psychology has been to combine general concepts with research of the individual child in all her complexity in everyday life activities. Psychologists such as Riegel, Bronfenbrenner, Burman, Morss, Hedegaard, and Walkerdine have criticized research approaches that study child development from a functional view.…

This article suggests that the principle of object-relatedness, introduced by Vygotsky and expanded by A. N. Leontiev, can be used to conceptualize human subjectivity within a profoundly social view of human development. This is achieved by reformulating the premises of cultural-historical activity theory to include the notion that material…

This article offers an introduction to the central concepts and principles of the Systemic-Structural Theory of Activity (SSTA), an activity-theoretical approach specifically tailored to the analysis and design of human work. In activity theory, cognition is understood both as a process and as a structured system of actions. Building on the…