Figure 1.  Culture as process.  This schematic shows some idealized relations between natural, internal, and artifactual structure and how they interact over time.  The arrows represent the propagation of constraints.  Constraints may be propagated by many means.  For instance, natural structure may be “perceived” and artifactual structure “produced” via internal structure and the mechanisms which translate properties of one medium (eg., a distribution of light) into properties of another (eg., a distribution of sound which may have social import).  The cover term "coordination" is sometimes used to refer to the satisfaction of constraints (i.e., the translation which takes place between media so as to enable functional properties, eg., the establishment of intersubjectivity or shared expectations about a situation) no matter the mechanism by which constraint satisfaction is achieved.  The diagram is simplified (for the sake of clarity) by letting the labels for structures stand for undifferentiated populations of those structures.  Thus the diagram does not include the fact that “internal structure” entails many structures and processes private to many individuals yet which are constructed through situated learning in shared environments.  See Figure 58 for an individual-centered version of this schematic.  (Adapted from Hutchins and Hazlehurst, 1991.)