evidence (n.)

In language ACQUISITION, the DATA needed to enable a child to acquire knowledge of a language. Two types of evidence are commonly identified, following CHOMSKYAN principles: positive evidence refers to the actually occurring UTTERANCES available to the child in its environment; negative evidence refers to the various indications about what is not ACCEPTABLE, such as parental corrections and explanations (‘direct negative evidence’), and the avoidance of certain sentence patterns (‘indirect negative evidence’). The claim that these types of evidence are so limited (the POVERTY OF THE STIMULUS argument) underpins the view that some knowledge of language must be innate.