Page "Abstraction" Paragraph 24

Abstraction is frequently applied in linguistics so as to allow phenomena of language to be analyzed at the desired level of detail.

A commonly considered abstraction is the phoneme, which abstracts speech sounds in such a way as to neglect details that cannot serve to differentiate meaning.

Other analogous kinds of abstractions ( sometimes called " emic units ") considered by linguists include morphemes, graphemes and lexemes.