Central to piaget's theory is the concept of imitation adaptation self-efficacy scaffolding

Adaptation is the concept proposed by Jean Piaget, the term accommodation is part of the process of adaptation that involves altering existing ideas and schemes, as a result of new experiences in the learning process. It is part of Piaget's cognitive theory and studies.

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.