Full context:   Mary Douglas, a British Functionalist, extended Turner's theory of ritual structure and anti-structure with her own contrasting set of terms "grid" and "group" in the book Natural Symbols. Drawing on Levi-Strauss' Structuralist approach, she saw ritual as symbolic communication that constrained social behaviour. Grid is a scale referring to the degree to which a symbolic system is a shared frame of reference. Group refers to the degree people are tied into a tightly knit community. When graphed on two intersecting axes, four quadrants are possible: strong group/strong grid, strong group/weak grid, weak group/weak grid, weak group/strong grid. Douglas argued that societies with strong group or strong grid were marked by more ritual activity than those weak in either group or grid. (see also, section below)