Chomsky 🧠

"Data of performance provide evidence about the nature of the internal system, particularly so when they are refined by experiment, as in standard field work. 

"But even the most massive collection of data is necessarily misleading in crucial ways. It keeps to what is normally produced, not the knowledge of the language coded in the brain, the primary object under investigation for those who want to understand the nature of language and its use.

"That internal object determines infinitely many possibilities of a kind that will not be used in normal behavior because of factors irrelevant to language, like short-term memory constraints, topics studied 60 years ago. 

"Observed data will also include much that lies outside the system coded in the brain, often conscious use of language in ways that violate the rules for rhetorical purposes. 

"These are truisms known to all field workers, who rely on elicitation techniques with informants, basically experiments, to yield a refined corpus that excludes irrelevant restrictions and deviant expressions. 

"The same is true when linguists use themselves as informants, a perfectly sensible and normal procedure, common in the history of psychology up to the present.

"Proceeding further with normal science, we find that the internal processes and elements of the language cannot be detected by inspection of observed phenomena. 

"Often these elements do not even appear in speech (or writing), though their effects, often subtle, can be detected. 

"That is yet another reason why restriction to observed phenomena, as in LLM approaches, sharply limits understanding of the internal processes that are the core objects of inquiry into the nature of language, its acquisition and use. 

"But that is not relevant if concern for science and understanding have been abandoned in favor of other goals."