Mapping Principle (in syntax)
In syntax, the Mapping Principle is a principle proposed in Marantz (1984) to relate independently constructed levels of representation to each other. In Marantz's model there are three levels of syntactic representation, logico-semantic structure (l-s-structure), syntactic structure (s-structure), and surface structure, together with a lexicon whose lexical entries contain information about argument structure, transitivity, semantic roles etc. The Mapping Principle guarantees that crucial aspects of structure, specifically those relating to grammatical relations, are automatically preserved from one level to the next.
Marantz, Alec. 1984. On the Nature of Grammatical Relations. Cambridge, MA: MIT Press.