A further criticism of Krashen's theories is levelled at his repudiation of grammar instruction. Critics claim that some kind of direct focus on grammar is both beneficial and necessary - see Long (1998). Krashen (2003), after a comprehensive analysis of the research data in these two areas, concludes that neither learner output nor grammar focus have any direct influence on acquisition. He states that his hypotheses " .. have not only survived well over the years but have also proven to be useful in other areas of language education. So far, research results remain consistent with these hypotheses and there is no counterevidence."
Error analysis was a component of contrastive analysis, sometimes known as the 'weak' version of the . The 'strong' version sought to predict rather than explain errors, using the differences between the learners' first and second languages.
Contrastive Analysis Hypothesis (CAH), and error analysis together ..
Modern research on L2 acquisition is rooted in , a viewpoint popular in the 1950s and which sought to explain and predict errors in language learning based on a comparison of the and of the learner's L1 versus the 'target' L2. Though contrastive analysis mostly gave way to theories of L2 acquisition that better-reflected new insights from modern , and , it continues to be a tool for spotting potential problems for teaching in the classroom, and as a potential explanation for errors in naturalistic performance - i.e. the understanding and production of spontaneous language by learners.