[...] a theory of computational lexical semantics needs to make reference to four levels of representations: [...] "Qualia structure" defines the essential attributes of objects, events, and relations, associated with a lexical item. By positing separate components [...] in what is, in essence, an argument structure for nominals, nouns are elevated from the status of being passive arguments to active functions.
- Pustejovsky & Boguraev (2004), a pag.342