Apparent discrepancy exists between Schmidt's Noticing Hypothesis and Krashen's Input Hypothesis. Whilst Krashen highlights the importance of comprehensible input and asserts that language is acquired unconciously, the notion of conscious learning has gained wide support from Schmidt and other researchers. They argue that noticing enhances second language development as one crucial level of consciousness. By reviewing the theoretical constructs that underlie the role of noticing, this paper aims to justify the role of noticing as one crucial level of consciousness in enhancing second language learning.
