As a developmental psychologist, I often find in the developmental literature references to mechanisms and processes of developmental change. However, the distinction between them is rarely, if ever, clarified. As I see it, mechanisms of DC are concrete, material and relatively easy to see or detect and are, in terms of time, anterior to what they bring about. For example, M of C is what is operating when a clock functions or works. In contradistinction, I think that P of C are interior and they have to be inferred because they are not visible. For instance, in Piaget's theory, assimilation and equilibration are processes, not mechanisms of change. To put it simply, mechanisms of DC are linked to "the why" of developmental, whereas processes of DC are linked to "the how" of development. I would much appreciate receiving inputs from RG researchers to my question and positing.