Pertains to knowledge representation, including the structure and organisation of concepts in the human conceptual system. Can relate to stable or temporary knowledge structures assembled for purposes of local meaning construction. Cognitive linguists have modelled conceptual structure in terms of relatively stable knowledge structures such as a domain (1), a cognitive model, a semantic frame, an idealised cognitive model and different kinds of conceptual projection including cross-domain mappings such as metaphor. Conceptual structure has also been modelled in terms of mental space formation, the establishment of a mental spaces lattice and the formation of a conceptual integration network.