The focus on errors made by second language (L2) learners and Corrective Feedback (CF) _ called as negative evidence, repair, negative feedback and focus-on-form by linguists, discourse analysts, psychologists and those who work recently on classroom Second Language Acquisition (SLA) respectively _ had been exist on almost every movement that had took place in the area of language teaching and learning (Lyster & Ranta, 1997). In 1950s and 1960s behaviorists believed that errors can damage learning and should be corrected immediately. "Recently, those working within the interactionist framework (e.g. Long, 1996) maintain that since CF enables learners to make connections between form and meaning in the context of communication, it is important for acquisition" (Golshan & Ramachandra, 2012, p. 120). The role of feedback is also evident in structural and communicative approaches in which "â€¦ feedback is viewed as a means of fostering learner motivation and ensuring linguistic accuracy" (Ellis, 2009, p. 3). Owing to such attention given to error treatment, scholars were interested to know how they could respond learners' errors which results in effective teaching of L2 and how they should behave in different contexts to have a long lasting effect on learners' language.
Review of related literature
Making the nature of CF clear many studies had done and researchers investigated different questions aroused around this issue, for example Lyater and Ranta, in 1997, observed four French immersion classroom to find the different types of corrective feedback, their distribution in communicatively oriented classroom and the distribution of uptake following different types of corrective feedback. Four years later in 2001, Lyster reviewed the recordings again. This time he tried to find the answer to two other questions that were not discussed in Lyster and Ranta (1997): "1.what types of learners errors lead to what types of corrective feedback? 2. What types of corrective feedback lead to the immediate repair of what types of learner errors?"(Lyster, 2001, p. 275) Samar and Shayestefar (2009), in Iran, analyzed their database made from observing two EFL classrooms to find how EFL teacher error treatment in terms of CFs vary across these classrooms and what type of CFs leads to learners uptake and successful repair. Related to this issue Balighizadeh and Abdi (2010) mentioned that language learning and corrective feedback bound up together and make an appropriate language learning environment. They believed that the function of feedback is more apparent in EFL contexts which teacher is the only source for answering students' questions and feedback giving.
Ellis (2009) wrote that corrective feedback "takes the form of a response to a learner utterance containing a linguistic error" (p. 3). This erroneous utterance could be delivered in the form of an oral production of L2 or a piece of writing that means teachers can give feedback to both writing and speaking of L2 learners. "Bitchener (2008) points out to this issue that there may be prominent differences between SLA work in oral and written feedback in second language acquisition writing studies"( as cited in Soori, Kafipour & soury, 2011, p. 497). Therefore this paper only focuses on corrective feedback which is given to oral erroneous utterances. According to previous study done by Lyster and Ranta (1997) these utterances consist of nonnative-like uses of L2 which they classified them to phonological, lexical or grammatical errors and in some cases when more than one type of error occurred in a student turn (e.g. phonological+ lexical) this is called "multiple" (p. 45). "The response can consist of (1) an indication that an error has been committed, (2) provision of the correct target language form, (3) Metalinguistic information about the nature of the error or (4) any combination of these" (Soori, Kafipour & Soury, 2011, p. 495). Six types of CFs first reported by Lyster and Ranta (1997), therefore, divided into two categories by Soori, Kafipour and Soury based on the way they treat learners' errors. This kind of classification established on the basis of information-processing model "â€¦ which describes skill acquisition as a gradual change in knowledge from declarative to procedural mental representations" (Ding, n.d., p.88). Therefore giving the correct form helps learners to boost their declarative knowledge_ knowledge of a language system_ but giving metalinguistic information helps learners to increase control over their already internalized declarative knowledge which means to increase their procedural knowledge (Ding, n.d.).
Types of corrective feedback
Lyster and Ranta (1997) distinguished six different types of feedback in their study and Ding (n.d.) added English examples to these CF types
Explicit correction refers to the explicit provision of the correct form. As the teacher provides the correct form, he or she clearly indicates that what the student had said was in correct. (e. g. "Oh, you mean," "you should say"). (1) L (learner): and three pear (sounds like bear). T (teacher): not beer. Pear.
Recasts involve the teacher's reformulation of all or part of the student's utterance minus the error. (2) T: when you were in school? L: yes. I stand in the first row. T: you stood in the first row? L: yes, in the first row, and sit, ah, sat the first row
Clarification requests indicate to students that the utterance is ill-formed in some way and that a repetition or reformulation is required. This is a feedback type that can refer to problems in either comprehensibility or accuracy, or both. (3) L: why does he fly to Korea last year? T: Pardon? L: why did he fly to Korea last year?
Metalinguistic feedback contain either comments, information, or questions related to how well-formed the student's utterance is, without explicitly providing the correct form. (4) L: I went to the train station and pick up my aunt. T: Use past tense consistently. L: I went to the train station and picked up my aunt.
Elicitation refers to techniques that teachers use to directly elicit the correct form from the student. Teachers can elicit completion of their own utterance by strategically pausing to allow students to "fill in the blank", or use questions such as "How we do X in English?" to elicit correct forms, or directly ask students to formulate their utterance. (5) L: once upon a time, there lives a poor girl named Cinderella T: once upon a time, thereâ€¦ L: there lived a girl.
Repetition refers to a teacher's repetition, in isolation, of a student's erroneous utterance. In most cases, teachers adjust their intonation so as to highlight the error. (6) L: Mrs Jones travel a lot last year. T: Mrs Jones travel a lot last year? L: Mrs Jones traveled a lot last year.
Two other strategies that are used in L2 classrooms are clarification request and paralinguistic signals (Ellis, 2009). Paralinguistic studies most of the time accompanied with recasts in order to make them more explicit for students.
"A construct closely related to provision of CF is uptake" (Samar & Shayestefar, 2009, p. 110). Lyster and Ranta(1997) introduced uptake as:
Uptake in our model refers to a student's utterance that immediately follows the teacher's feedback and that constitutes a reaction in some way to the teacher's intention to draw attention to some aspect of the student's initial utterance (this overall intention is clear to the student although the teacher's specific linguistic focus may not be). (p. 49)
The data revealed that uptake of students could have two types, sometimes their errors repair completely and sometimes uptakes need repair and the students may produce the utterance with another type of error which it is the teacher that should give CF again.
Classification of corrective feedback types
Explicit feedback vs. implicit
As it is written in Ding (n.d), a popular classification of CFs is to divide them according to their explicitness and implicitness. Yang asserted that "In the case of implicit feedback, there is no overt indicator that an error has been committed, whereas in explicit feedback types there is" (as cited in Ding, n.d., p. 86). Long (as cited in Ding, n.d.) asserted that recast is a form of implicit feedback and can be easily neglected, especially in a meaning-focused context. Balighizadeh and Abdi (2010) had mentioned that "â€¦ because they are not explicit, do not isolate the features of language form that are the focus of feedback, and do not interrupt_ even briefly_ the flow of meaningful interaction" (p.59). Lyster (2001) had found a different result. He found that recast most of the time accompanied with another strategy such as repetition or paralinguistic signal or raising stress on the part that error occurred which make the recast less implicit. Other researchers which compared the effects of recasts and metalinguistic information on delayed performance of L2 learners proposed that "interactional feedback in the form of metalinguistic informationâ€¦might have been more effective than recasts because learners might be more likely to perceive it as overtly corrective" (as cited in Balighizadeh & Abdi, 2010, p.64). Ding (n.d.) stated that "this dichotomous classification of feedback can be problematic" (p. 86). Another classification which tried to prevent such vagueness and was the focus of Ding paper is dividing the CF strategies into recasts and prompts.
Recasts vs. prompts
Lyster (2001) introduced the term negotiation of form which he placed four Cf strategies (i.e. elicitation, metalinguistic clues, clarification requests, and repetition of error) under its rubric. All of these strategies lead to peer- or self-repair and therefore lead to a high rate of uptake. While recasts and explicit correction provide the correct answer and therefore they do not lead to peer- or self-repair. This distinction is clearly expressed by Lyster (2001): "recasts and explicit correction are thus distinguishable from the negotiation of form in that the former supplies correct forms that learners may or may not repeat, whereas the latter provides signals to facilitate peer- and self-repair" (p.274). Negotiation of form is called prompt according to Ding's (n.d.) studies. "Because recasts provide language learners with target-like reformulations and exemplars, they account for a significant part of language input in L2 classrooms, while prompts encourage learners to produce their own target-like output" (p.87).
Lyster and Ranta (1997) analysed their database in order to find the relationship between feedback type and learner uptake. According to them the most popular feedback technique used by teachers in their project was recast which turn out to be a technique that results the least uptake of any kind (i.e. repair and need-repair). Clarification request, metalinguistic feedback, and repetition are similar in eliciting uptake from students, and it should be mentioned that metalinguistic feedback was more successful than clarification request and repetition. "The most successful technique for eliciting uptake is elicitation: All learner utterances following elicitation involve uptake with an almost even distribution between repair and need-repair" (Lyster & Ranta, 1997, p.54). From these results it can be concluded that the techniques that lead to peer- or self-correction should be used more in form-focused activities. The more students notice the feedback and the more they involve in processing the language items the more uptake results.
In order to answer two questions proposed by Lyster (2001) that was mentioned in this paper, Lyster examined the relationship among error types, feedback type, and repair. He found that "grammatical and phonological errors tended to invite recasts, whereas lexical errors tended to invite negotiation of form more often than recast" (Lyster, 2001, p. 287), And " the majority of phonological repairs were learner repetitions following recasts and the majority of grammatical and lexical repairs were peer- and self-repairs following negotiation of form" (Lyster, 2001, p. 288). Lyster stated that
although the majority of the feedback following grammatical errors involved recasts, the majority of grammatical repairs followed the negotiation of form. Conversely, lexical and phonological repairs resulted, for the most part, from the different feedback types that these error types tended to invite. (Lyster, 2001, p. 285)
Samar and Shayestefar's (2009) finding was in accordance with Lyster. According to them the recast the most employed feedback (i.e. recast), is the most likely to lead no uptake. "Metalinguistic and explicit corrections are the most successful types of feedback leading to successful uptakeâ€¦ with metalinguistic more successful at eliciting repair" (Samar &Shayestefar, 2009, p.125
Although the findings of different researchers are the same, but it cannot be said that these results are conclusive (Tedick, 1998). Tedick (1998) offered four suggestions for teachers based on the experiences of her colleague_ Ms. De Gortari. According to her an English language teacher shoul (1) consider the context, (2) become aware of his current practices, (3) practice a variety of feedback techniques, and (4) focus on the learner _ it is important to let the learner self-correct. Therefore it is important for teachers to become aware of different techniques of Cf and use the findings of researchers in order to gain the best result from their action. If they are working on form, negotiation of form is preferred and suggested, if they are working on fluency and meaning it is better to correct them unobtrusively.