To put it plainly, no mat¬ter how well discourse is organized or how brilliant the writer's ideas may be, it would be hard to understand them if the language is opaque. | 48 CHAPTER 3 correction is to help L2 writers become independent editors of their own text. To achieve this objective both teachers and students need to be aware that all errors are not created equal. Many studies have addressed the gravity of errors in the perceptions of university faculty Vann Lorenz Meyer 1991 Vann Meyer Lorenz 1984 . For example as mentioned earlier among other researchers Santos 1988 found that lexical and semantic errors are often considered to be particularly grievous in L2 academic text. Other reports note that grammar errors also vary in their importance to the L2 text quality. According to studies cited in this section the most egregious grammar errors include word order verb tense word morphology word form -deletion in cleft constructions relative adjective clauses subject-verb agreement. Errors that have less impact on evaluations of student text include articles prepositions comma splices spelling Above all however studies of error gravity and other investigations have established clearly that faculty in the disciplines are far less tolerant of NNS than NS errors and view L2 language-related errors as sufficiently important to negatively affect their overall evaluations Byrd Reid 1998 Ferris Hedgcock 1998 . Thus teaching students to become independent self-editors represents a crucial component of writing instruction. Some approaches to teaching L2 writing advocate text-level editing only as the final stage of writing after matters of discourse organization and content are addressed. However because the ultimate objective of editing instruction is to teach students essential self-editing skills that can be useful for the duration of their academic careers working on lexical and grammar errors can take place at any point of essay development Ashwell 2000 . Self-editing instruction can proceed in stages and be selective. The first step is to raise students awareness of ubiquitous and egregious errors and improve noticing skills. Editing
