This is the original version of Principles and
I have changed my position on only one issue: At the end of Principles and Practice, Isuggest the use of a form of deception -students may think they are acquiring vocabulary or learning subject matter, but unknown to them, they are acquiring because they are getting comprehensible input at the same time. I now think it is very important to make a strong effort to inform students about the process of language acquisition, so they can continue to improve on their own.
Krashen, S. (1989)We acquire vocabulary and spelling by reading: Additional evidence for the input hypothesis.