Halliday & Matthiessen (1999: 87-8):
Semantic types in different taxonomic regions are distinguished according to different criteria; and they have different sets of roles. But the different criteria and sets of roles are construed within the grammar. …(i) Phenomena within different taxonomic regions are classified according to different kinds of grammatically construed criteria. For example:(a) perception (figures: subtype of sensing): according to means of perceiving: see (means: eyes)/ hear (means: ears)/ smell (means: nose)/...(b) transformation (figures: subtype of doing): according to result, e.g. break (result: into pieces)/ melt (result: into liquid state)/ shrink (result: smaller)/ pulverise (result: powder, dust)/...(c) motion (figures: subtype of doing): according to manner, location, purpose, e.g. fall (location: downwards)/ stroll (purpose: for pleasure)/ flee (purpose: to escape)/ walk (manner: with legs, fairly slowly)/...(d) higher animals (elements: subtype of conscious thing, at the taxonomic depth of species): according to epithets of age and sex, e.g. cow (sex: female, age: adult), bull (sex: male, age: adult), calf (age: nonadult).(e) artefacts (elements: a subtype of object): according to material, purpose, e.g. containers (purpose: to contain substances) — barrel (material: wood), basket (material: cane or other woven material), basin (material: metal), bowl (material: earthenware or glass).(ii) Phenomena within different domains have different grammatically construed structural roles associated with them. For example:(a) perception: perceiver & phenomenon being perceived;(b) concrete thing (elements: subtype of object): various epithets, specifically of physical dimensions such as size, shape, weight, colour and age.(c) weight (elements: subtype of quality): tensor, showing degree of intensity.