Stephen Krashen is professor emeritus at the University of Southern California, who moved from the linguistics department to the faculty of the School of Education in 1994. He is a linguist, educational researcher, and activist.
Dr. Krashen has published more than 350 papers and books, contributing to the fields of second-language acquisition, bilingual education, and reading. He is credited with introducing various influential concepts and terms in the study of second-language acquisition, including the acquisition-learning hypothesis, the input hypothesis, the monitor hypothesis, the affective filter, and the natural order hypothesis. Most recently, Krashen promotes the use of free voluntary reading during second-language acquisition, which he says "is the most powerful tool we have in language education, first and second."
As education policy in Krashen’s home state of California became increasingly hostile to bilingualism, he responded with research critical of the new policies, public speaking engagements, and with letters written to newspaper editors. During the campaign to enact an anti-bilingual education law in California in 1998, known as Proposition 227, Krashen campaigned aggressively in public forums, media talk shows, and conducted numerous interviews with journalists writing on the subject. After other anti-bilingual education campaigns and attempts to enact regressive language education policies surfaced around the country, by 2006 it was estimated that Krashen had submitted well over 1,000 letters to editors.
In a front-page New Times Los Angeles article published just a week before the vote on Proposition 227, Jill Stewart penned an aggressive article titled 'Krashen Burn' in which she characterized Krashen as wedded to the monied interests of a "multi-million-dollar bilingual education industry." Stewart critically spoke of Krashen as the father of bilingual education. Krashen has been widely criticized in conservative and nativist political circles due to his influence on the field of language minority education, second-language acquisition, and his efforts to educate the public on matters related to English language learners in schools.