Descriptive analysis must be based upon what people say. [...] it means that the written form of the language is entirely secondary (in fact, quite irrilevant) so far as the descriptive linguist is concerned. [...] this principle of basing description on the spoken form of the language means that the linguist records the actual forms employed rather than regularizing the data or evaluating utterances on the basis of some literal dialect.
- Nida (1949), a pag.1-2