Responses to learners' errors have been researched in the fields of language teaching, language acquisition, and cognitive psychology under the terms corrective feedback, negative evidence, and negative feedback respectively (El Tatawy, 2002). Although there is a general consensus on the positive role of feedback in second language acquisition, researchers have different views on the way corrective feedback is presented (Carroll & Swain, 1993; Ellis, 2008; Fotos, 1993; Nassaji & Swain, 2000). This study aims at investigating the effects of strategic feedbacks rooted in Vygotsky's sociocultural theory (SCT) on second language learners' listening comprehension processes.
2. Literature Review
Ellis (2008) points out that the research shows the increasing use of recasts or indirect correction by teachers in the classroom but there is no certainty about whether or not recasts result in acquisition. He further emphasizes that one should also know whether the corrected forms produced by the learners as a result of teacher recasts can be elicited in the learners' future independent performance.
Researchers have tried to determine whether implicit feedbacks through recasts are more helpful for the development of L2 or an explicit feedback presented by means of metalinguistic explanation or direct correction. Ellis et al. (2009) surveyed 11 studies and concluded that explicit corrective feedback is more advantageous. However, in some studies they observed no advantage for either type of feedback. Ellis et al. (2009) note that making strong statement about feedback type is difficult because the studies they surveyed were different in terms of design (observational vs. experimental), measures of learning (mechanical vs. communicative), and focus (input-processing vs. output-processing). Apart from the studies they surveyed, Ellis et al. (2009) reported the result of their own study in which they compared the role of implicit feedbacks (recasts) with explicit feedbacks (repetition of error accompanied by metalinguistic explanation) in learning English past tense marker (-ed). They concluded that "explicit feedback seems more likely to promote the cognitive comparison that aids learning" (p. 330).
Nassaji and Swain (2000) argue that Vygotsky's sociocultural stance on error correction- dynamic assessment (DA)- can provide new and important insights into the L2 learning process. The authors confer on a seminal work undertaken by Aljaafreh and Lantolf (1994) as an exemplary study for implementing an SCT-based approach to negative feedback. In this study, as they explain, error correction proved effective to the extent that it was negotiated between the learner and the teacher and was provided at the right point or within the learner's zone of proximal development. They argue that three principles should govern the provision of feedbacks during interactionist DA. The first principle is graduation which states that the feedback should be strategic in the sense that the tutor should offer the most appropriate level of assistance in a way that learner functions at his or her full potential. In the first place the learner's ZPD needs to be identified so that appropriate level of assistance is offered. Another principle governing the interactionist DA is contingency which states that once the learner shows signs of self-control, the assistance should be withdrawn. Interactionist ZPD assessment is also informed by the principle of dialogic negotiation. In interactionist DA, it is through an interactive, dialogic negotiation that the true status of ZPD is discovered. Dialogue is an indispensable component of Vygotsky's theory of mental development. Through a dialogic interaction, the tutor and learner establish a sense of intersubjectivity(i.e., a temporarily shared social world) whereby appropriate mediation is offered (Wood, Bruner, & Rose, 1976).
Nassaji and Swain (2000, p. 35) contend that "what distinguishes this perspective from the conventional perspective is that in this framework, error correction is considered as a social activity involving joint participation and meaningful transactions between the learner and the teacher". In this vein, Lantolf and Poehner (2010, p. 18) explain that an extremely important point in error correction from a Vygotskian standpoint is that mediation should be adjusted to the learner's performance which entails "co-regulation [my italic] whereby a learner's responsiveness to teacher mediation also regulates the teacher and her subsequent attempts at assisting the learner" and "it is in this process of coregulation that learner agency and autonomy emerge". They further clarify that the main difference between mediation as it is defined in SCT and error correction as it is operationalized in the SLA literature is "the simultaneous development of an appropriate product and a sense of agency and eventually autonomy in using the language" (p.18). A contribution this study hopes to make is that it intends to assume feedback not as being dichotomized into two levels only, as it is in the SLA literature, but as a continuum consisting of multiple levels represented in degrees.
According to Rogoff and Gardner (1984), group learning in Vygotskian perspective fleshes out the principle of 'proleptic instruction', an idea which underscores the active but guided role of the novice in an interaction with a more capable other. Proleptic instruction is associated with the concept of 'liberatory education' due to its focus on the recognition of the novice's rights to engage in the interaction to the extent that he can share responsibility in determining the direction of the learning activity and in constructing a shared understanding of situation (Freire, 1970). Drawing on Poehner (2009), a major gap in the literature on DA is the lack of studies on group learning and how the individuals can together experience developmental processes. In the research on L2 listening, the need for a diagnostic test is an acute one. The present study represents a step towards surfacing these shortcomings.
2.1 Group Dynamic Assessment
According to Poehner (2009), the essence of social mediation (i.e., feedbacks) and interaction within the microcosm of class should be explored under a new framework known as group dynamic assessment (G-DA). Inspired by Vygotsky's sociocultural theory of mind and specially his concept of ZPD, this G-DA-based study rests on the assumption that it is possible to engage a group of learners in collaboratively coconstructing a group's ZPD while catering to each individual's ZPD (Shabani, Khatib & Ebadi, 2010). Moreover, it argues that through joint efforts the group might function in ways that are beyond the present capabilities of any individual member (Gibbons, 2003). Like Poehner (2009), we take the group's ZPD as the ability a group of learners can collectively manifest when engaged in a task performance. Our theoretical stance also reflects Nyikos and Hashimoto’s (1997) statement that, within a group, aside from an individual ZPD, each person has an additional zone of potential which is shaped when a group of learners share cooperatively their abilities for successful completion of a task. They argue that a number of individual ZPDs working together in a joint activity form a group zone or group ZPD. The main concern here is not to identify an individual learner's ZPD or whether a single learner progresses as a result of teacher's intervention but how a collection of individual ZPDs together were able to accomplish the task and coconstruct collective scaffolds (i.e., a group ZPD) under the support of teacher's strategic feedbacks. In other words, whether an individual is or is not able to perform the task is not our concern; instead what gains prominence is that throughout the interactions, the teacher’s attention should remain fixed on the group's ZPD rather than the individual ZPDs (Poehner, 2009).
This study, therefore, is an attempt to test Donato's (1994) concept of 'collective scaffolding', which implies that once encountering a comprehension obstacle, the contributions from each individual, albeit in piecemeal and in different forms (i.e., phonological, syntactic, lexical or semantic) can provide supportive scaffolds for other members and help the group to collectively solve the problem. Through joint problem-solving, each linguistic cue offered by the group members or mediator can prove vital in disambiguating the comprehension problems.
2.2 Research Questions
Quite precisely, to meet the purposes of the study the following questions were raised:
Characterized by a longitudinal and microgenetic design, the study lasted about two months during which the learners received G-DA instruction and feedbacks. Moreover, it is of an 'intrinsic' case study type (Stake, 1995) with the aim to closely examine a particular group's performances in the real-life context for an in-depth analysis of its nuances. More precisely, a number of exemplary works served as the theoretical basis to guide the research design of this study namely Poehner's (2005, 2009), Ableeva's (2010) and Aljaafreh and Lantolf's (1994). The schematic representation of the design of the present study is as follows:
Schematic Representation of Assessment Sessions
pretest (NDA + DA)
enrichment program (EP)
posttest (NDA + DA)
This study involved 20 undergraduate learners of English major recruited from a nonprofit college. The learners had spent three semesters at the college studying English. They were both males and females ranging in age between 20 and 24. An announcement was made on holding a special reinforcement course of listening. A total of 25 learners volunteered to take part in the study, out of whom 20 were selected based on their availability and free time. We found this procedure quite in line with one of the assumptions underlying the DA, which states that learners' motivation and willingness to learn is a methodological prerequisite for the success of DA (Poehner, 2010). The teacher of the class (i.e., author) had a good knowledge of the principles and tenets underlying the DA both theoretically and practically.
The following considerations were taken into account when selecting the listening texts for this study:
1. The texts should be authentic and genre specific. To meet this condition, all the texts were selected from the VOA news broadcasts;
2. All the texts used in the pretest were similar in terms of topic, pace of delivery and level of difficulty but not identical;
3. The texts should be relevant to the requirements of the course. The texts were selected from authentic news broadcasts. The main reason behind the selection of media discourse as the main text type for classroom practice was the observation that for many learners of English the ability to understand news broadcasts is the 'holy grail' of second language listening performance (Cross, 2009). The author's focus on this type of genre had the advantage of recruiting subjects consisting of highly motivated learners, a theoretical and methodological prerequisite for implementation of G-DA.
3.3 Data Collection
All the assessment sessions, including the pretest, posttest and TR sessions, were audio recorded on MP4 player for later qualitative analysis. A limitation encountered was that the learners did not consent to the visual recording; hence, parts of the features related to the face-to-face interactions such as the role of gestures and body posture remained unknown. After the data collection, all recorded data were studied, transcribed (as needed) and analyzed. The related data were transcribed using the transcription conventions adapted from Johnson (1995). This transcription system helped decode several discourse-related features of face-to-face interactions like interjections, learners' L1 (Farsi) recalls and so on.
3.4 Data Analysis
The qualitative analysis of the data in this study reflects Vygotsky's microgenetic approach to the concept of the Zone of Proximal Development. This approach rests on the assumption that "We must not measure the child, we must interpret the child" (Vygotsky, 1998, p. 204) and the assessor should try "to penetrate into the internal causal-dynamic and genetic connections that determine the process itself of mental development" (Vygotsky, 1987, p. 203). The unit of analysis was dialogic interactions, an approach that reflects Vygotsky's SCT methodology and view of development. The microgenetic method was used to uncover the quality of mediational moves across the assessment sessions. The analysis of G-DA protocols aimed at uncovering the learners' process of listening comprehension. The analyses were carried out to diagnose the strategic feedbacks and the effects of G-DA instruction- comprising the effects of collective scaffolding and peer mediation as well as the critical role of different types of cues on the learners' listening performance within the social microcosm of the classroom context.
Each assessment session was characterized by two phases, an NDA (nondynamic assessment) elicitation stage which aimed at surfacing the class's ZAD (Zone of Actual Development) or current status and a G-DA intervention phase. The decision to administer the NDA and DA sessions simultaneously reflects Poehner's (2005) suggestion that in DA we do not need to hold an NDA test separately since the DA procedure has the dual function of detecting learners' ZAD and ZPD. More precisely, the class sessions were held as follows:
First, you will listen to a VOA clip. Then, I will play the file again and make pauses during which you have to provide your recalls. You need to provide your recall orally and in English to the extent possible. When recalling the text, try to focus on the main ideas and provide supporting ideas and details of the text.
The microgenetic analysis of the learners' performances was made at two levels: the completion of the task and the amount and quality of mediation used to help the learners understand the text. The analysis helped detect signs of struggles and development. To observe the effects of G-DA-based feedbacks on the learners’ listening comprehension processes sections of the corpus where strategic feedbacks were found effective are reported. The Table 2 illustrates the types and frequencies of learners' listening difficulties in assisted DA sessions:
Type and Frequency of Learners' Listening Difficulties
Source of Difficulty
In our qualitative analysis of the protocols, we intend to address the raised two questions together because we observed the instances of error identification and learners' enhanced performance in each interaction. The observation confirmed the inherent potential of DA which is characterized by an evolutional and instructional function. Each protocol showed the instances of both learners' listening problems and their improvements. The following protocols exemplify the diagnostic and developmental potential of G-DA strategic feedback.
[…calling Israel and the Palestinians to take concrete steps toward easing tension and building confidence.
1. T: what did you hear?
2. Ss: [silent]
3. T: What are Israel and Palestinians going to do?
4. S1: take concrete steps
5. S2: for building confidence
6. T: Good, what else? Listen again.
7. S3: they are going to take concrete steps for building confidence @ and easy tension
8. T: good, but is that 'easy'? Did you hear /i: / at the end of the word?
9. S4: @'easing' tension?
10. T: That’s it.
In this episode, after posing several questions to the class and gaining access to the learners' decoding (lines 4, 5, & 7), the mediator identifies the misconceived word. The partial recalls by learners 1 and 2 paved the ground for a more complete recall by learner 3 but with a single word being misunderstood. Having elicited the misunderstood word from learner 3 (line 7), the mediator reproduces it in an incredulous tone (line 8) to implicitly state that his recall includes an incorrect word. This mediation (i.e., reproducing the recall in a questioning tone) proves beneficial for learner 4 who eventually offers the correct word (line 9).
Signs of struggle on the learners' part and their on-the-spot guesses during listening could also be observed in the following protocol.
[As the death toll rises, the true extent of the damage is difficult, if not impossible, to assess.]
1. T: Let's listen. [The teacher plays the segment to the class.] What did the speaker say?
2. S1: death toll rises
3. S2: it is difficult to access
4. T: access?
5. Ss: [silent]
6. T: What is the issue he is talking about?
7. Ss: [silent]
8. T: what words did you hear?
9. S2: death toll
10. S3: damage
11. T: Good, then what is difficult to do according to the speaker?
12. S4: [silent]
13. T: Is the last word ‘access’!?
14. Ss: [silent]
15. S5: maybe 'assess'
16. Ss: yes, 'assess'.
17. S6: The speaker is saying that because of increase of death it is difficult to
assess the damage.
18. T: That's right.
What is evident in this protocol is that the learners misunderstood the speaker's sentence, a comprehension problem originating in the verb 'assess' which outwardly carried the semantic load of the utterance. The learners had mixed up the verb 'assess' with 'access' which was phonetically very similar but didn’t match with other neighboring words to reinforce an acceptable inference. When engulfed with such an unresolved phonological obstacle crippling their comprehension they had no option other than remaining silent when asked to explain the content (line 12). The teacher intervened by directly asking the learners to turn their focus next time to the last word only and check it against other parts of the sentence (a strategic feedback more explicit than reproducing the recall in a questioning tone). As in the previous episodes, the teacher's response in this interaction takes a skeptical tone twice (line 4 and 13), which signals the inaccuracy of the response (i.e. 'access'). This helps learner 5 to suggest the correct option (line 14), which is then confirmed by learner 6 (line 16) and fully recalled by learner 6 (line 17). This extract shows how the G-DA can uncover the source of learners’ comprehension problem. In this interaction, learners’ deficit knowledge of phonology serves as a problem trigger.
In some cases learners were found unable to recognize a known word because of their inability to decode one of its sounds or syllables. The protocol below demonstrates the role of G-DA in surfacing this phonological problem:
[We have the government buildings there that are in ruins.]
1. T: What did you hear?
2. S1: we have government buildings @
3. T: Good, what else?
4. Ss: [silent]
5. T: what are the words after ‘buildings’?
6. Ss: that are
7. T: good, after that?
8. Ss: [silent]
9. S2: /u: nz/!
10. S3: @ /u: inz/
11. T: Good, but what did you hear before /u: /?
12. S1: # ruins, ruins!
13. T: Great! What does it mean?
14. S4: destroy
In this interaction, the learners’ problem seemed to originate from their inability to receive the initial sound of /r/ in ‘ruins’ which impeded their comprehension of the word. But, teacher's attention-focusing strategy brought to their attention the initial sound that tended to skip their attention (lines 4-10). Upon reception of such consciousness-raising, learner 1 was able to correctly guess the initial sound and also the entire word (line 12).
This episode, in the words of Vandergrift (2006, p. 15), highlights the fact that "learners need to learn to match the aural form of a word in concatenated speech with the word in their mental lexicon".
In the following protocol, learners were given the required consciousness-raising but the ability to accomplish the task lay much beyond their ZPD:
[This country is immune to the kind of political unrest that’s hit Egypt.]
1. T: What did you hear?
2. S1: this country
3. T: Good, what else?
4. S2: is immune to political unrest
5. T: Great! What is the meaning of 'immune'?
6. S2: it means 'masoon budan' ^ (to be exempt from)
7. T: Right, and 'unrest' means
8. S3: 'naarami' ^ (unrest)
9. T: Good. What are the words after 'unrest'?
10. S3: That's it Egypt.
11. T: What does this last part mean?
12. Ss: [silent]
13. T: Is that ‘it’?
14. Ss: [silent]
15. T: What does 'that's it Egypt' mean?
16. Ss: [silent]
17. T: it is not 'that's it Egypt’, it is 'THAT'S HIT Egypt'. 'That's' is the contraction for 'THAT HAS' which is followed by 'HIT Egypt'. 'Hit' is the verb used in its past participle form. [The teacher writes the segment on the board]
This interaction began with the teacher checking the learners' independent recall of the first part of the sentence and, then, the meaning of some key words like ‘immune’ and ‘unrest’. Next, the mediator asked the class to recall the last part of the sentence. Contrary to his expectation, he found the learners unable to correctly recall the ending relative clause, which apparently didn’t contain any unfamiliar word. He wanted the class to reproduce that part along with its meaning. Learner 3 imitated the speaker pronouncing it the same way as he did (line 10) but was unable to make sense of it. No other learner could make any contribution either (line 12). Upon the reception of this response, the mediator identified the source of learners' problem. He reasoned that the last part proved senseless because of the learners’ miscomprehension of the contracted segment (i.e., 'that's hit'), which turned out to be similar in pronunciation to 'that's it'. He surmised that the source of learners' confusion lay in their failure to decode the initial /h/ of ‘hit’. In order to let the class understand the source of their confusion, the teacher embarked on explaining the necessary linguistic tips. In this episode, after using the mediational strategy of focusing three times and facing learners’ repeated failure to provide the correct recall, the teacher was compelled to reason that the ability to recognize the spoken form of a known word like ‘hit’ in connected speech is beyond the learners' ZPD.
[Speaking at a rally in Damascus, Khaled called the American plan a farce.]
[Speaking at a rally in Damascus, Khaled called the American plan a farce.]
1. T: Who can paraphrase this sentence?
2. S1: Khaled was speaking in a rally and @
3. S2: Khaled was speaking in a rally in Damascus and then
4. T: Good, who was speaking?
5. Ss: khaled
6. T: where?
7. Ss: at rally in Damascus
8. T: That's right. And the last part?
9. Ss: [silent]
10. S3: he called American plan a Fars?!
11. T: What did he call the American plan?
12. S3: /fa: rs/?
13. S4: Farsi? ^ [Farsi]
14. Ss: [silent]
15. T: Fars? You could use your dictionary to whether it is Farsi or something else.
16. S3: Farce is a comedy, a humorous play, f-a-r-c-e
17. T: That's it
In this interaction, the mediator asks several questions about the content of the sentence so as to gain access to the learners' independent recalls. He found the learners unable to figure out the meaning of the last part of the sentence (line 9). Then, he replayed that segment in hopes to strengthen their comprehension. This mediation helped learner 3 to recall the entire segment (line 10) but only in a regurgitated fashion because when he was asked to give the meaning of 'farce' in his recall (line 12) he was only able to articulate the word without bringing its sense. He might have mixed up the word with a homophonous and more familiar term (i.e. Fars; that is, noun form of Farsi, learners' mother tongue). At this juncture, learner 4 also made a hunch committing the same error (line 13). Then, the mediator got sure that the word 'farce' must have been totally new to learners 3 and 4 and possibly other learners as well. Therefore, he asked the class to look the word up in their dictionaries and check its meaning. This interaction shows the learners' inability to understand a sentence due to the inadequacy of their lexical knowledge.
On a number of occasions, some segments in the input sentence raised obstacles in the learners' comprehension of the text, a problem originating in the lack of, or limited exposure to, the required grammatical knowledge. Protocol 6 below showcases the learners' mediated recognition of the lexical constituents of a segment but their recurrent failure to decipher its content due to their unfamiliarity with a certain grammatical structure.
[Underscoring the difficulties, Palestinian militants fired several attacks at Israel….]
1. T: Ok, what did the speaker say?
2. S1: Palestinians fired attacks at Israel
3. T: Good, Palestinians what?
4. S2: Palestinian militants
5. T: militant means?
6. S2: jangju, mobarez ^ (combatant, military man)
7. T: That’s right. But, what about the first part? What did the speaker say
8. Ss: [silent]
9. S3: difficulties
10. T: good, what else?
11. S4: underscoring
12. S5: underscoring
13. T: Good, what is the meaning of underscoring?
14. Ss: [silent]
15. T: it means ‘highlighting’, ‘emphasizing’. Now, who can paraphrase
the entire sentence? You could also say it in Persian.
16. Ss: [silent]
17. T: here the speaker is saying that ‘while the militants emphasized that they had
many difficulties, they attacked Israel'.
Here, learners could understand a great deal of the sentence and recalled the main clause appropriately (lines 2-6) but faced some difficulty in processing the first part of the sentence. Further replaying helped them pick up the segment ‘underscoring the difficulties’ (lines 8-12) but they were still unable to make head or tail of it. In order to detect the exact source of learners' difficulty, the mediator asked them to provide the meaning of 'underscoring' but he received no response which indicated that they had never heard the word before. Then, he gave the meaning of the word hoping that it would solve their problem. But, learners continued to have problems in understanding and retelling the sentence even in their L1 (line 16). The mediator was then compelled to assume that learners' problem was not lexical and had its roots in their inadequate grammatical base and, more particularly, their unfamiliarity with the dangling structure.
This episode confirms the potential role of G-DA feedbacks in surfacing learners' inadequate grammatical knowledge as a source of comprehension problem through mediated dialogue and interaction, a property which is absent in non-dynamic assessments.
[Today, the minister reiterated US demands for Hamas to stop stirring up trouble.]
1. T: ok, now let's see what the speaker said.
2. S1: minister demands for Hamas
3. S2: minister demands Hamas to stop trouble
4. T: Good, what else?
5. Ss: [silent]
6. T: Let's listen again
7. Ss: [silent]
8. T: what is the word after ‘minister’?
9. S3: irritated?
10. T: Did you hear /i:/ in the beginning? Listen.
11. S2: no, it is /ri: /
12. T: Good, and then what did you hear after 're-'?
13. S3: @ I think it is /i: /
14. T: exactly, so we have /ri: / and then /i: /. Great, what else?
15. S4: the next one is /t/
16. T: That's it. So far, we have picked up 'ri:-', then /i: / and after that /t/. Now, you
could refer to your dictionary to find the rest of the word. You need to go to the R
section and find a word with an initial /r i: i: t/-
17. S4: is that ‘retreat’?
18. T: Did you hear long /i: / or /ei/ after the second /r/? Listen again.
19. S4: /ei/
20. T: so it is not 'retreat'. Check out other possibilities. Remember, so far
we have received /ri: i: treit/
21. S5: I think it is 'reiterate'
22. T: that's it. What does it mean?
23. S5: It means 'say again'
24. T: This is the correct word. But now let’s check the word after ‘stop’…
Following learners' correct but incomplete recalls in lines 2 and 3, the teacher asks them to bring the word after 'minister' but observes their silence. Then, he replays the segment containing the unfamiliar word ‘reiterate’ a number of times and receives an incorrect response (i.e., irritate in line 9). The teacher focuses learners' attention on the initial sounds of the word to guide them towards the correct choice through phonological consciousness-raising. He asks the class whether they hear /i:/at the start which helps prompt the correct recall of the first syllable (line 11). He then proceeds to decode the remaining sounds of the word in a lockstep fashion until he elicits the beginning sounds of the word (i.e. /r i: i: t/) plus the last subsequent syllable (i.e., /treit/). Once decoding the constituent sounds and syllables of the word, the teacher asked the class to open up their dictionaries and find a word carrying the decoded sounds while he offered his next guidelines on where and how to look through the dictionary (line 16). Learner 4 came up with the word ‘retreat’ (line 17), an incorrect surmise that stimulated the teacher to ask for a comparison of pronunciation of the last syllable of 'retreat' with that of the word in question. This meta-linguistic reminder complemented by a re-listening helped learner 5 to arrive at the correct word (i.e. ‘reiterate’) and give its meaning (lines 21& 23).
This interaction also reveals how short dialogic exchanges between the teacher and learners who took turns to share their contributions with the teacher culminated in a correct response. The way the teacher interacted with individual learners with his focus remaining fixed on the class’s ZPD is an evidence for the evolvement of concurrent G-DA. The proleptic instruction proceeding in a lockstep fashion was found conducive to the realization of collective scaffolding, a source of assistance that benefitted a sizable number of secondary interactants.
This study examined the effects of G-DA feedbacks on the learners’ listening comprehension processes. The microgenetic analysis of mediator-learners' dialogic interactions was presented in a systematic way and illustrated with protocols from the assessment sessions.The analysis proceeded to illustrate the potential role of G-DA feedbacks in bringing to surface the underlying causes of learners’ listening difficulties. A number of factors affecting listening comprehension were identified that were classified into three main categories namely phonological, lexical and grammatical. The phonological difficulty appeared mostly in the form of confusing one word with another and not recognizing a known word (protocols 2 & 3). Inadequate lexical knowledge was another frequent source of difficulty that appeared in the form of not understanding the received words that was resolved either implicitly through G-DA interactions or explicitly through overt explanations (protocol 1). The third source of difficulty was a gap in learners' grammatical knowledge, which took the form of ignoring a known grammar point or not knowing a certain grammatical structure (protocol 6). The identification of aforementioned sources of difficulties afforded deeper insights into the learners’ comprehension processes which altogether attest to the quality of G-DA feedbacks in diagnosing learners' listening comprehension and offering an informed, finely-tuned, and contingent instruction/mediation. The results also speak to the fact that L2 phonology was a serious contributor to breakdowns in listening comprehension. Aside from phonology, poorly developed lexis and grammar could account for much of the difficulty in the L2 listeners' comprehension processes. The analysis of the protocols also confirmed the important role of collective scaffolding and mediatory moves of individual learners in stretching the group ZPD to the accomplishment of listening problems that surpassed the limits of individuals' ZPDs (See protocols 5 & 7).
Learners' ability to understand authentic English news texts in unmediated conditions was consistently recorded at a lower level. However, when engaged in mediated dialogues, the learners displayed an improved performance and a better understanding of the texts. Viewed from SCT perspective, this observation indicates that learners were involved in an activity i.e. listening to a news broadcast, which was within their ZPD and that the mediation was necessary for development to occur.
The learners engaged in class interactions as active constructors of knowledge rather than passive input crunchers, an observation confirming Vygotsky's Activity Theory that learning is first social and then individual and that before gaining an ability to engage successfully in independent cognitive processes (self-regulatory activities) learners experience these processes with others (Donato, 1994; Lantolf, 2008). Supportive of Activity Theory, learners' performances displayed the three important features of motive, goal and operation.
On encountering learners' failure to make a successful recall, the teacher engaged the learners in more strategic questioning, responding with a wide range of mediational strategies rather than providing the solution right away. Therefore, his reaction entailed more of a 'learning-focused' assessment (Poehner, 2007) and his strategic mediations represented attempts to bring the learners into a negotiable ZPD. Such a caring role on the part of the teacher enhanced the validity of assessment procedures deployed, a characteristic that typifies classroom-based assessments in general.
The mediatory moves exchanged between the primary interactants served as mediatory input to benefit the rest of the group who played the role of secondary interactants but active participants nonetheless. The teacher (mediator) posed a leading question or prompt to the group which the individuals felt responsible to answer. The replies and contributions, albeit in piecemeal, by primary interactants were found beneficial for the secondary interactants and, subsequently, for the enhancement of group ZPD. The mediatory exchanges could be taken as examples of concurrent G-DA interactions (e.g., See protocol 7) which shifted rapidly between primary and secondary interactants with the teacher moving the entire class forward in its ZPD while negotiating with individual learners in their respective ZPD.
The G-DA which was based on such DA principles as contingency, graduation and dialogic collaboration (Aljaafreh & Lantolf, 1994) showcased a systematic and principled instruction rather than a haphazard, hit-or-miss presentation which characterizes the teacher-fronted education.
The study placed on its agenda an exploration of the diagnostic potential of G-DA in surfacing the learners' listening comprehension difficulties and a sketch of the mediator’s on-the-spot mediation to redress them. The influential factors affecting the learners' listening difficulties were found to be phonological, lexical and grammatical. It was found that consciousness-raising at these levels could significantly enhance the learners' comprehension processes.
It was also found that G-DA could help foster coconstruction of knowledge among a group of L2 learners in the regular classroom instruction. The minute analysis revealed that mediatory moves and contributions from primary interactants could play a vital role in encouraging participation of secondary interactants. The participation of a sizable number of individuals in the interactions proved conducive to the creation of collective scaffolding in the course of which individual members benefitted from the G-DA feedbacks in the social space of the classroom. The mediator's G-DA hints and leading questions demanded from each person involvement in 'a joint intellectual activity' and 'pooling of mental efforts' to collaboratively accomplish the task (Petrovsky, 1985). The partial contributions by volunteer learners were piled up to erect a scaffold for another participatory learner to arrive at the correct answer. The interactions substantiated the critical role of the mediator's 'proleptic instruction', namely a problem-solving activity proceeding in a lockstep fashion (Rogoff & Gardner, 1984) in creating a joint activity in which individuals' contributions paved the way for the collective's access to the required knowledge to overcome the listening problems.
In a nutshell, this study depicted the class as a cohesive unit for constituting a collective through which individual learners working cohesively as active members of the group collaborated together to erect scaffold for each other for realizing a common goal. The G-DA-based strategic feedbacks exemplified a proleptic instruction with the teacher offering a host of other-regulation strategies, which differed from the out-dated teacher-fronted trainings wherein an expert injects unilaterally his inputs into the novice's mind. The G-DA showcased a sample of libratory education by engaging the novices in a joint activity while recognizing their rights to share equal responsibility for determining the direction of the learning task. This observed constructivist methodology reflecting Vygotskian thinking is a serious departure from banking education and transmissional pedagogy which reduces teaching to an act of depositing information and asking learners to receive, memorize and repeat (Freire, 1970; Kumaravadivelu, 2001).
Finally, on implication side and in the research on L2 feedbacks the study recommends the use of G-DA-based strategic feedbacks as a more valid assessment and instructional tool than the traditional SLA-based feedbacks to diagnose and enhance the learners' listening comprehension abilities in the classroom context.