The noticing hypothesis was proposed by Richard Schmidt in 1990. He stated that features of language

Language

Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...

 cannot be learned unless they have been noticed. Noticing alone does not mean it is automatically acquired, but it is the essential starting point. Still debated is the question whether a learner must consciously notice something. This hypothesis is part of cognitivist

Cognitivism (psychology)

In psychology, cognitivism is a theoretical framework for understanding the mind that came into usage in the 1950s. The movement was a response to behaviorism, which cognitivists said neglected to explain cognition...

 perspective of second language acquisition

Second language acquisition

Second-language acquisition or second-language learning is the process by which people learn a second language. Second-language acquisition is also the name of the scientific discipline devoted to studying that process...

.