Teacher’s corrective feedback on the pronunciation of English fricatives and affricates by non-English major freshmen at the Diplomatic Academy of Vietnam

---o0o--- NGUYỄN THANH THỦY TEACHER’S CORRECTIVE FEEDBACK ON THE PRONUNCIATION OF ENGLISH FRICATIVES AND AFFRICATES BY NON-ENGLISH MAJOR FRESHMEN AT THE DIPLOMATIC ACADEMY OF VIETNAM

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NGUYỄN THANH THỦY

TEACHER’S CORRECTIVE FEEDBACK ON THE

PRONUNCIATION OF ENGLISH FRICATIVES AND AFFRICATES BY NON-ENGLISH MAJOR FRESHMEN

AT THE DIPLOMATIC ACADEMY OF VIETNAM

Phản hồi chữa lỗi của giáo viên đối với cách phát âm các phụ âm xát

và tắc xát trong tiếng Anh của sinh viên năm thứ nhất không chuyên

tiếng Anh ở Học viện Ngoại giao

M.A MINOR PROGRAMME THESIS

FIELD: ENGLISH TEACHING METHODOLOGY CODE: 60140111

FACULTY OF POST-GRADUATE STUDIES

-o0o -

NGUYỄN THANH THỦY

TEACHER’S CORRECTIVE FEEDBACK ON THE

PRONUNCIATION OF ENGLISH FRICATIVES AND AFFRICATES BY NON-ENGLISH MAJOR FRESHMEN

AT THE DIPLOMATIC ACADEMY OF VIETNAM

Phản hồi chữa lỗi của giáo viên đối với cách phát âm các phụ âm xát

và tắc xát trong tiếng Anh của sinh viên năm thứ nhất không chuyên

tiếng Anh ở Học viện Ngoại giao

M.A MINOR PROGRAMME THESIS

FIELD: ENGLISH TEACHING METHODOLOGY CODE: 60140111

SUPERVISOR: DR DƯƠNG THỊ NỤ

Hanoi, 2015

I, Nguyễn Thanh Thủy, K21, being a candidate for the degree of Master of Arts hereby declare that the MA thesis entitled Teacher’s Explicit Corrective Feedback on the Pronunciation of English Fricatives and Affricates by Non-English Major Freshmen at the Diplomatic Academy of Vietnam is my original work under the strict guidance of my supervisor No part in the thesis has been copied or reproduced by me from any other person’s work without acknowledgements Furthermore, the thesis has been adjusted according to valuable comments of the examination board

Prof Hoàng Văn Vân

Supervisor

Dr Dương Thị Nụ

This paper would not have been completed had it not been for the beneficial help of many people, to all of whom I am indebted

First and foremost, I owe an enormous debt of gratefulness to my supervisor

Dr Dương Thị Nụ for her constant support, guidance and insightful comments which were fundamental factors in the completion of the study

In addition, sincere thanks are due to the teachers and students in class KT40B at the Diplomatic Academy of Vietnam for allowing me to administer the test and questionnaire schedule during their precious class time

I also cannot find words to express my gratitude to Ms Julia Williams, Ms

Đỗ Hải Hà, Ms Đinh Thị Mai Anh, Ms Nguyễn Thị Huyền Trang, and Ms Nguyễn Thùy Nhung for their invaluable assistance during the experimental period

Furthermore, I would like to express my thankfulness to my parents, my friends, and my classmates for their continual encouragement during the time I conducted this research

Last but not least, I would like to show appreciation to my readers for their interest and criticism on the thesis

It is undeniable that English has become one of the most popular foreign languages in Vietnam However, though Vietnamese learners can speak English, not many of them have intelligible English pronunciation The fact remains that they are unlikely to perceive their pronunciation mistakes when speaking Such pronunciation mistakes will be fossilized if they are not corrected by the teacher

Of 24 English consonants, the six consonants /s, z, ʃ, ʒ, ʤ, ʧ/ have been identified as the most common pronunciation problems that non-English major freshmen at the Diplomatic Academy of Vietnam encounter As a result, the present study aims to help them overcome these problems In order to achieve the aim of the study, a quasi-experimental design was conducted on 36 non-English major freshmen in class KT40B at the Diplomatic Academy of Vietnam Besides, after the experimental period, a short questionnaire was distributed to the experimental group

to explore their opinions about the use of Teacher’s Explicit Corrective Feedback in English speaking lessons

The results of the study indicate that students’ pronunciation of the six English consonants improves significantly when they are provided with Teacher’s Explicit Corrective Feedback Furthermore, the use of this corrective feedback type also receives support from the experimental students Based on the findings, the thesis provides some recommendations for the application of Teacher’s Explicit Corrective Feedback, which would be of great assistance for university students in English speaking lessons

Table 1: English Consonants

Table 2: Similarities and Differences of English Alveolar Fricatives,

Alveo-Palatal Fricatives and Affricates Table 3: Percentile Rank of the Pre-test Scores of KT40B Students

Table 4: Placements of 34 Subjects in Pairs for Random Assignment Table 5: Frequency of the Pre-test Scores

Table 6: The Scoring Process in the Experimental Subgroup 1

Table 7: The Scoring Process in the Experimental Subgroup 2

Table 8: Results of the Pre-test and Post-test of Both Groups

Table 9: Comparison of the Pre-test Scores of Two Groups

Table 9a: Paired-samples Statistics (Pair 1)

Table 9b: Paired-samples T-test (Pair 1)

Table 10: Comparison of the Gain Scores Made by Two Groups after the

Experimental Period Table 10a: Paired-samples Statistics (Pair 2)

Table 10b: Paired-samples T-test (Pair 2)

Table 11: Comparison of the Post-test Scores of Two Groups

Table 11a: Paired-samples Statistics (Pair 3)

Table 11b: Pair-samples T-test (Pair 3)

Table 12: The Experimental Group’s Opinions about TECF on Their

Pronunciation of the Six Consonants /s, z, ʃ, ʒ, ʤ, ʧ/

Lists of Figures

Figure 1: The Process of Providing Pronunciation-Focused TECF on Students’

Output Figure 2: Differences in Gain Scores Obtained by Both groups after the

Experiment Figure 3: The Experimental Group’s Opinion about TECF on Their

Pronunciation of the Six Consonants /s, z, ʃ, ʒ, ʤ, ʧ/

Lists of Abbreviations

DAV: Diplomatic Academy of Vietnam

TCF: Teacher’s Corrective Feedback

TECF: Teacher’s Explicit Corrective Feedback

ACKNOWLEDGEMENT i

ABSTRACT ii

LISTS OF TABLES iii

LISTS OF FIGURES AND ABBREVIATIONS iv

PART A: INTRODUCTION 1

I Statement of the Problem and Rationale of the Study 1

II Aim and Objectives of the Study 3

III Research Hypothesis and Research Questions 4

III.1 Research Hypothesis 4

III.2 Research Questions 4

IV Scope of the Study 5

V Methodology 5

VI Significance of the Study 6

VII An Overview of the Rest of the Paper 6

PART B: DEVELOPMENT 8

CHAPTER I: LITERATURE REVIEW 8

I.1 The Importance of Pronunciation Teaching and Learning 8

I.2 Aspects of Pronunciation 9

I.3 The Aim of Teaching Pronunciation: Intelligibility 10

I.4 General Description of Consonants and English Consonants 12

I.5 English Fricative Consonants 14

I.5.1 Production of English Alveolar Fricatives: /s, z/ 14

I.5.2 Production of English Alveo-palatal Fricatives: /ʃ, ʒ/ 15

I.6 English Affricates: /ʤ, ʧ/ 15 I.7 Previous Studies on Vietnamese Learners’ Pronunciation of the Six

I.8.2 Types of Teacher’s Corrective Feedback 19

I.9 Teacher’s Explicit Corrective Feedback 21

I.10 Theoretical and Empirical Background on TECF 23

I.10.1 Theoretical Background on TECF 23

I.10.2 Empirical Background on TECF 25

I.11 Research Gap 26

CHAPTER II: METHODOLOGY 27

II.1 Context of the Study 27

II.2 Study Design 28

II.3 Selection of the Main Subjects for the Study 31

II.4 Assignment of the Subjects to the Experimental and Control Group 32

II.5 Instruments for Data Collection 35

II.6 Instrument for Data Analysis 39

II.7 Treatment to the Experimental Group and Control Group 40

II.8 Integration of Pronunciation Targets into the English speaking lessons 47 CHAPTER III: RESULTS 51

III.1 Comparison of the Pre-test and Post-test Scores 51

III.1.1 Comparison of the Pre-test Scores of Both Groups 52

III.1.2 Comparison of the Gain Scores of Both Groups after the Experiment 53

III.1.3 Comparison of the Post-test Scores of Both Groups 56

III.2 The Experimental Group’s Opinions about TECF on their Pronunciation of the Six English Consonants /s, z, ʃ, ʒ, ʤ, ʧ/ 57

CHAPTER IV: DISCUSSION 61

IV.1 Discussion of Both Groups’ Pronunciation Gain Scores and Post-test Scores after the Experimental Period 61

Speaking Lessons 65

PART C: CONCLUSION 67

I Conclusion 67

II Limitations of the Study 68

III Recommendations for Further Studies 69

REFERENCES 70

APPENDICES I APPENDIX 1: PRE-TEST II APPENDIX 2: POST-TEST V APPENDIX 3: PICTURE DESCRIPTION ACTIVITY VIII APPENDIX 4: QUESTIONNAIRE (ENGLISH) X APPENDIX 5: QUESTIONNAIRE (VIETNAMESE) XI

PART A: INTRODUCTION

This chapter sheds light on the research problem and rationale of the study as well as its scope and significance More importantly, the aim and objectives of the study are emphasized with its research questions Finally, the chapter concludes with an overview of the rest of the paper, which serves as an orientation for readers throughout the research

I Statement of the Problem and Rationale of the Study

As a member of World Trade Organization, Vietnam has given foreign languages in general and English in particular a greater role than ever before for the purpose of attracting foreign investment and promoting the economy As English is widely used in many international settings, the ability to communicate in real-life situations is of great importance Therefore, of four English skills, speaking plays an integral part in every school’s English curriculum throughout the country

In the process of improving speaking skills, many learners face the problem

of pronunciation In fact, according to many foreigners, Vietnamese learners can speak English; however, not many of them have intelligible English pronunciation

so that they can be understood easily in direct communication with foreigners (Duong, 2009) In her view, the low level of communicative competence of learners

is directly attributed to their deficiencies in pronunciation, not vocabulary and grammar This is the justification of why teaching pronunciation needs to be given priority

For two years working at the Diplomatic Academy of Vietnam (DAV), the researcher has realized that most of her first-year students show few improvements

in pronunciation after two semesters although they are required to speak English in all English lessons In other words, their frequent mistakes tend to be maintained as the first days they entered the Academy Through direct observation in many English speaking lessons at DAV, of 24 English consonants, two alveolar fricatives

/s, z/, two alveo-palatal fricatives /ʃ, ʒ/ and affricates /ʤ, ʧ/ have been identified as the most common pronunciation mistakes of the researcher’s students They have also been more confirmed after considerable discussion with many teachers at DAV

For instance, most of the students tend to pronounce the word social as /ˈsəʊsl/ instead

of /ˈsəʊʃl/, or television as /ˈtelɪvɪzn/ instead of /ˈtelɪvɪʒn/

The fact remains that learners with poor pronunciation at the segmental level are not always at an advantage In Tench (1981, p.17-20, as cited in Chung),

“spoken language is a social act, and you are expected to fulfill many of the listener’s expectations and needs.” Therefore, “the more of these are violated, the harder it will be on the listener, and the more “points” will be taken off by listeners

in their judgment of the speaker” (Chung, p.2) This view is echoed by Yates (2002, p.1) who believes, “we often judge people by the way they speak, and so learners with poor pronunciation may be judged as incompetent or lacking in knowledge.” That is the reason why the researcher finds it necessary to teach her first-year students how to pronounce individual sounds correctly because it will serve as a foundation for better speaking competence in the next three years In order words, they need to start with individual sounds before moving on other complicated aspects of speech such as intonation, stress, etc

With regard to the coursebooks used by freshmen in English speaking

lessons at DAV, namely Let’s talk 2 in the first semester and Let’s talk 3 in the

second semester, they do not consist of any sort of pronunciation work on individual sounds Instead, they contain a variety of speaking activities for the purpose of developing students’ oral communication skills and fluency The employment of these books presumes students to acquire basic knowledge of pronunciation, including English consonants, to get involved in different English conversations However, in many situations, when a student delivers a talk, mistakes like /ˈsəʊsl/ and /ˈtelɪvɪzn/ seem not to be perceived Furthermore, those

who are less likely to notice such pronunciation mistakes are non-English majors

From the researcher’s viewpoint, the problem lies in the fact that students do not receive adequate feedback from the teacher on their pronunciation performance

In other words, they need to be assisted by the teacher to realize their problems Kenworthy (1987, p.2) comments:

Learners need to know what to pay attention to and what to work on Because speaking is for the most part unconsciously controlled, learners may miss something important For example, they may not realize that when a particular word is stressed or said in a different way this can affect the message that is sent to the listener Teachers need to make learners aware of the potential of sounds (Kenworthy, 1987, p.2)

It is suggested that Teacher’s Corrective Feedback (TCF) can be used to help learners perceive and discard what is unacceptable or inappropriate from their interlanguage In simple words, the students will have a clear picture of what they are weak at and what they need to improve Considering the benefits TCF can bring

to learners of English, the researcher wants to determine if TCF can solve her students’ pronunciation problems in terms of the six English consonants /s, z, ʃ, ʒ,

ʤ, ʧ/ in English speaking lessons where pronunciation work is not included

Last but not least, research into TCF on pronunciation mistakes in English speaking lessons at university level in Vietnam is quite small in number All the aforementioned reasons have motivated the researcher to conduct this quasi-experimental research on Teacher’s Corrective Feedback on the pronunciation

of English fricative and affricate consonants by non-English major freshmen at the Diplomatic Academy of Vietnam

II Aim and Objectives of the Study

The study aims at helping non-English major freshmen at DAV improve their pronunciation of the six consonants /s, z, ʃ, ʒ, ʤ, ʧ/

To be specific, the primary objectives of the study are as follows:

 To examine the effect of TECF on the pronunciation of the six consonants /s, z,

ʃ, ʒ, ʤ, ʧ/ by non-English major freshmen at DAV;

 To investigate the experimental students’ opinions about TECF on their pronunciation of the six consonants /s, z, ʃ, ʒ, ʤ, ʧ/ after the experimental period

III Research Hypothesis and Research Questions

III.1 Research Hypothesis

A hypothesis is constructed for the purpose of achieving the aim of the study:

H1: Non-English major freshmen who receive TECF make more significant improvements in their pronunciation of the six consonants /s, z, ʃ, ʒ, ʤ, ʧ/ than those who do not receive TECF

If the above hypothesis is fully accepted, the following null hypothesis will

be obviously rejected or vice versa:

Ho: There is no difference in the pronunciation of the six consonants /s, z, ʃ,

ʒ, ʤ, ʧ/ between non-English major freshmen who receive TECF and those who do not

In order to identify which hypothesis will be accepted, the first research question, posed in Section III.2, needs to be satisfactorily answered

III.2 Research Questions

Based on the aim and objectives of the study, two questions were formulated and needed to be satisfactorily answered:

(1) What is the difference that Teacher’s Explicit Corrective Feedback brings about

in the pronunciation of the six consonants /s, z, ʃ, ʒ, ʤ, ʧ/ by non-English major freshmen at the Diplomatic Academy of Vietnam?

(2) What are the experimental group’s opinions about Teacher’s Explicit Corrective Feedback on their pronunciation of the six consonants /s, z, ʃ, ʒ, ʤ, ʧ/ after the experiment period?

IV Scope of the Study

Initially, corrective feedback as stated in the research title is, in fact, confined

to Explicit Corrective Feedback, one type of TCF in a study of Ellis, Loewen & Erlam (2006, as cited in Fawbush, 2010), for the reasons elaborated on in the Literature Review Chapter

Regarding English fricative consonants, the study focuses on two English alveolar fricatives /s, z/ and two alveo-palatal fricatives /ʃ, ʒ/ When it comes to English affricate consonants, they are /ʤ, ʧ/ Only issues concerning the pronunciation

of these sounds are taken into consideration

Finally, it should be noticed that 36 non-English major freshmen in the class KT40B at DAV were involved in the study but only 34 students were eligible to become its main subjects The process of selection will be elaborated in the Methodology Chapter

TECF on their pronunciation mistakes regarding /s, z, ʃ, ʒ, ʤ, ʧ/ after the experiment

VI Significance of the Study:

As one of the trail-blazing studies on the impact of TECF on the pronunciation of English consonant sounds by Vietnamese university students, the study would be of great benefit for two reasons:

Initially, the research outcome could be used as evidence of the impact of TECF on Vietnamese university students’ pronunciation of the six consonants /s, z,

ʃ, ʒ, ʤ, ʧ/, which are believed to be one of the biggest problems that most of them encounter As for English teachers in general and English teachers at DAV in particular, they could base themselves on the results of the paper to make informed decisions on whether TECF should be encouraged or not In fact, if there exists a positive link between TECF and students’ pronunciation of the six consonants /s, z, ʃ,

ʒ, ʤ, ʧ/, it can bring about a significant change in many English speaking lessons at colleges and universities, where pronunciation work is not included

In addition, this study can serve as a reliable source of related literature and a basis for other researchers, who share an interest in the topic, to start their future work from

VII An Overview of the Rest of the Paper:

The rest of the paper consists of two main parts:

PART B: DEVELOPMENT

This part is divided into three chapters:

CHAPTER I: LITERATURE REVIEW - establishes the solid foundation for the whole paper Besides clarifying the key terms such as pronunciation, intelligibility, English fricatives and affricates, Teacher’s Explicit Corrective Feedback, the chapter offers a critical review of related studies

CHAPTER II: METHODOLOGY - clarifies the reason why a quasi-experimental design is employed in this study Furthermore, it also elaborates on the context of the study, the selection of the main subjects, the instruments for data collection and analysis, and the treatment to the experimental and control group

CHAPTER III: RESULTS - presents and analyzes all the collected data to find out the answers to the research questions

CHAPTER IV: DISCUSSION - presents the researcher’s discussion based on the research findings Furthermore, it also offers some recommendations for the application of TECF in English speaking classrooms

PART C: CONCLUSION

This part summarizes all the major points raised in the paper Furthermore, it also indicates the limitations of the study as well as some suggestions for further studies

PART B: DEVELOPMENT

CHAPTER I: LITERATURE REVIEW

This chapter provides an overview of the literature related to this study, establishing a solid foundation for the whole paper Not only are key terms like pronunciation, intelligibility, English fricatives and affricates, Teacher’s Explicit Corrective Feedback clarified but background information about the key terms is also presented to ensure a thorough understanding of the research matters Besides, the research gap is also revealed in this chapter

I.1 The Importance of Pronunciation Teaching and Learning

Gilakjani (2012) considers pronunciation as a set of habits of producing sounds, which is acquired by repeating the sounds over and over again and by being corrected when they are pronounced wrongly In other words, when one learns to pronounce a second language, he/she is forming new habits of pronunciation and overcoming the bias of the first language (Cook, 1996) Pronunciation refers to the production of sounds that are used to make meaning Yates (2002) opines that:

Learners with good pronunciation in English are more likely to be understood even if they make errors in other areas, whereas learners whose pronunciation is difficult to understand will not be understood, even if their grammar is perfect! (Yates, 2002, p.1)

This opinion is echoed by Hebert (2002, as cited in Shooshtari, Mehrabi, & Mousavinia, 2013), who argues that knowing grammar and vocabulary is important but useless if the speaker fails to pronounce those structures and words correctly When mispronounced, even the simplest words can prevent learners from being understood To sum up, the deficiencies in pronunciation may negatively affect learners’ communicative competence Without proper pronunciation nobody can say that he/she knows the language Apparently, this is the approach of scholars and

researchers who consider students’ communicative efficiency as the main purpose

of teaching and learning any foreign language (Hammer, 2001; Yates, 2002; Hebert, 2002; Duong, 2009) Under this approach, the important role of pronunciation teaching and learning is emphasized As Harmer (2001) argues, pronunciation teaching not only helps students become aware of different sounds and sound features but also improve their speaking immeasurably:

…concentrating on sounds, showing where they are made in the mouth, making students aware of where words should be stressed – all these things give them extra information about spoken English and help them achieve the goal of improved comprehension and intelligibility (Harmer, 2001, p.183)

I.2 Aspects of Pronunciation

Basically, pronunciation involves features at segmental (micro) level and suprasegmental (macro) level The former includes individual vowels and consonants and the latter involves aspects beyond the level of an individual sound such as word, phrase, and sentence stress, intonation, and rhythm (Seferoglu, 2015,

as cited in Tran, 2009)

The issue of teaching segmentals and suprasegmentals is controversial On one hand, Coniam (2002, as cited in AbuSeileek) opines that segmental aspects draw some researchers’ attention because they are more easily explained and taught than the suprasegmental ones Burns (2003, as cited in Gilakjani, 2012) also recommends giving attention to segmental features because, in his opinion, phonemes are “sounds that, when pronounced incorrectly, can change the meaning

of the word.” On the other hand, as shown in some recent studies, there is a shift to suprasegmental aspects of the sound system According to Morley (1991), suprasegmental features of pronunciation should be taught because of their beneficial functions in interactive discourse This is echoed by Seferoglu (2005, as cited in Gilakjani, 2012) who emphasizes macro features as they help learners acquire communicative competence However, there are still researchers (Goodwin, 2001; Burn, 2003; Gilakjani, 2012; Moghaddam, Nasiri, Zarea, & Sepehrinia, 2012)

who have a more balanced view that a lack of intelligibility can be attributed to both micro and macro features so they are equally important The present study is based

on the belief that both segmental and suprasegmental features of pronunciation play

a significant role in improving communication competence However, at different stages of learning, attention should be paid to either or both of the two aspects As discussed in Section I in the Introduction part, the focus of the study is on segmental features instead of suprasegmental features

I.3 The Aim of Teaching Pronunciation: Intelligibility

In the 1970s, proponents of the audio-lingual approach emphasized the necessity of pronunciation teaching in second language/foreign language (L2/FL) classrooms They are ones who approved of the mastery of native-like pronunciation Later, the audio-lingual approach did not win support of L2/FL speech research evidence The reason is, according to Moyer (1999), very few adult learners achieve native-like pronunciation in their L2 Since then, pronunciation became an “unteachable” subject due to the inevitability of “foreign accents” (Flege, Munro, & Mackay, 1995; Levis, 2005)

However, these days, the interest in pronunciation teaching has begun to revive It is based on the premise that the ultimate goal of L2/FL speech learning is

to achieve “acceptable” pronunciation According to James (2010, as cited in

Gilakjani, 2012), a learner’s pronunciation has three basic levels:

 Level 1: People often do not understand what the speaker is saying The speaker uses the wrong sounds when making English words or uses the wrong prosodic features when making English sentences

 Level 2: People understand what the speaker is saying, but the speaker’s pronunciation is not pleasant to listen to because he or she has a distracting and/or heavy accent

 Level 3: People understand the speaker, and the speaker’s English is pleasant

to listen to This is called comfortable intelligibility - the goal of pronunciation teaching

According to Gilakjani (2012), a speaker has “acceptable” pronunciation when other people can understand what he says and the speaker’s English is pleasant to listen to Kenworthy (1987, p.13) provides a more operational definition that we can “put to work”: “The more words a listener is able to identify accurately when said by a particular speaker, the more intelligible that speaker is.” Because words are made up of sounds, it is necessary to talk about the issue of sound equivalence In practical terms, we are aiming for something “close enough” In

Kenworthy (1987, p.13), an intelligible sound is defined as one that the listener can

match with the sound a native speaker would use without too much difficulty

In fact, learners use a variety of strategies to cope with a new set of sounds However, some ways of coping may create problems In Kenworthy (1987), a number of learners’ pronunciation strategies leading to unintelligibility problems are shown clearly: (as the study only deals with segmental aspects, learners’ pronunciation strategies related to suprasegmental aspects will not be included in this paper)

 Sound substitutions: When a consonant of English does not occur in the learner’s mother tongue, the “missing” sound is substituted with something from the speaker’s first language The substitution of one consonant for another may cause serious confusion for listeners For instance, by substituting /z/ for /ʤ/, a Vietnamese learner would produce the word germ

as /zɜːm/ instead of /dʒɜːm/

 Sound deletions: The speaker leaves out a sound In the case of consonants, either a single consonant at the beginning, middle, or end of a word is deleted or one of the consonants in a cluster is removed to simplify the

cluster For instance, the word his without the final /s/ would sound like hit

The word devastating with the sound /s/ deleted would sound /ˈdevəteɪtɪŋ/, which is considered unintelligible

 Sound insertions: Non-native speakers may add sounds To illustrate, the learner adds the sound /s/ at the end of the words they pronounce, causing the problem of unintelligibility

Kenworthy (1987) also comments that “intelligibility” is often influenced by how familiar the interlocutor is to the speaker In her opinion, the teacher himself cannot make objective judgments of the intelligibility of his students She argues that the frequent interactions between the teacher and his students gradually enable him to “tune in to” their accent In simple words, Vietnamese teachers of English may find it easier to comprehend what Vietnamese learners say Therefore, it is afraid that students’ pronunciation problems that threaten intelligibility may be left untreated

I.4 General Description of Consonants and English Consonants

In articulatory phonetics, consonants are articulated in two ways: either it is produced by a closing movement of one of the vocal organs, forming such a narrow constriction that the sound of the air passing through can be heard; or the closing movement is complete, giving a total blockage The closing movement may be related to the lips, tongue, or throat, but the articulation of consonants is very different from that of vowels, which is relatively open and unimpeded (Roach, 1991)

English consonants can be classified according to three main phonetic features: place of articulation, manner of articulation and voicing Manner of articulation describes how the tongue, lips and other speech organs are involved in making a consonant Six manners of articulation are plosive (a complete obstruction

of the air), fricative (a continuous airflow through the mouth), affricate (a slow release of the closure), nasal (the air escaping freely through the nose), lateral (the air escaping laterally over the sides of the tongue) and approximant (vowel-like)

Place of articulation is where, in the vocal tract, the obstruction of a consonant occurs, and which speech organs are involved Places include bilabial (both lips), labiodental (the upper teeth and inner lower lip), dental (the tongue tip), alveolar (the tongue against the gum ridge), alveo-palatal (the tongue blade), palatal (the tongue), and velar (the tongue against the soft palate) As regards voicing, it refers

to the activity of the vocal cords When the vocal cords are wide apart, consonants are said to be voiceless (lenis) When the vocal cords are closely together and vibrating, consonants are said to be voiced (fortis) English consonants with their different features of production are described in Table 1

Table 1: English Consonants Manner of

Articulation

Place of Articulation Labial Labio-dental Dental Alveolar Alveo-palatal Velar Glottal Plosive

I.5 English Fricative Consonants

Fricatives are consonants with the characteristic that when they are produced, air escapes through a small passage and makes a hissing sound, which is sometimes called “friction” Fricatives are continuant consonants, because you can continue making them without interruption as long as you have enough air in your lungs (Roach, 1991)

The fortis fricatives /z, ʒ/ are said to be articulated with greater force than the lenis fricatives /s, ʃ/ and their friction noise is louder The lenis fricatives have very little or no voicing in the initial and final positions, but may be voiced when they occur between voiced sounds (Roach, 1991)

I.5.1 Production of English Alveolar Fricatives: /s, z/

These sounds are articulated with the soft palate being raised and the air cannot pass through the nose The tip and blade of the tongue make a light contact with the upper alveolar ridge, and the side rims of the tongue make a close contact with the upper side teeth The airstream escapes through the narrow groove in the center of the tongue and then causes friction between the tongue and the alveolar ridge /s/ differs from /z/ in the fact that while /s/ is a fortis (voiceless), e.g sip, rice, /z/ is a lenis (voiced) with voice from the throat, e.g zip, rise Both /s/ and /z/ can be

at the initial, medial and final positions (Roach, 1991)

I.5.2 Production of English Alveo-palatal Fricatives: /ʃ, ʒ/

With regard to /ʃ/ and /ʒ/, their place of articulation is partly palatal and partly alveolar The tongue is in contact with an area which is slightly further back than that for two sounds /s/ and /z/ If you make /s/ and then /ʃ/, you will feel your tongue move backwards The air escapes through a passage along the center of the tongue as in the case of /s/ and /z/, but the passage is a little wider /ʃ/ is a fortis, e.g shore, caution, whereas /ʒ/ is a lenis with voice from the throat, e.g garage, vision

Furthermore, in order to produce /ʃ/ and /ʒ/, most speakers have to round their lips, which is an important thing that differentiates them from /s/ and /z/ /ʃ/ and /ʒ/ can

be found in the initial, medial and final positions In the case of /ʒ/, however, the distribution is much more limited Very few English words begin with /ʒ/ This sound is commonly found in the medial position, e.g decision, measure, usually (Roach, 1991)

I.6 English Affricates: /ʤ, ʧ/

/ʧ/ and /ʤ/ are the only two alveo-palatal affricates in English (Roach, 1991) These sounds are articulated with the soft palate being raised and the nasal resonator

is shut off A closure made between the tip, blade, and rims of the tongue and the upper alveolar ridge and side teeth creates an obstacle to the air stream At the same time, the front of the tongue is raised towards the hard palate in readiness for the fricative release The closure is released slowly, the air escaping in a diffuse manner over the whole of the central surface of the tongue with friction occurring between the blade/front region of the tongue and the alveolar/front palatal section of the roof

of the mouth The vocal cords are wide apart for /ʃ/, but may be vibrating for all or part of /ʒ/ according to the situation of utterance /ʧ/is voiceless but /ʤ/ is voiced with voice from the throat

In Duong’s research (2009), the similarities and differences of the aforementioned sounds in terms of voicing, place of articulation and manner of articulation are clearly indicated They are shown as follows:

Table 2: Similarities and Differences of English Alveolar Fricatives,

Alveo-Palatal Fricatives and Affricates

Sound Voicing

Manner of articulation

Place of articulation Same Different Same Different Same Different

A number of studies have been conducted to find out the common problems

of Vietnamese learners regarding English consonants in general and six English consonants /s, z, ʃ, ʒ, ʤ, ʧ/ in particular First, when it comes to the problem of sound deletion, /s/ in the medial position is often omitted Similarly, the omission of the two ending sounds /s/ and /z/ are frequent The reason lies in the fact that

Vietnamese speakers, in their language, do not have to pronounce the ending sounds (Duong, 2009; Ha, 2005) In addition, the three sounds /ʒ, ʤ, ʧ/ are not included in the Vietnamese consonant system; as a result, these sounds are really difficult for Vietnamese learners to produce, especially when they occur at the end of the words (Nguyen, 2007; Tran, 2009) Tran (2009) also opines that most Vietnamese learners are unfamiliar with “the act of holding the tongue against the alveolar ridge for the air to pass through with some friction.” As a result, it is the habit of “swallowing” ending sounds in the mother tongue that “inhibits the pronunciation of ending sounds in the target language” (Ha, 2005; Nguyen, 2007; Tran, 2009) Second, with regard to sound substitutions, Duong (2009), in the light of Hanoi dialect, finds out four sound pairs that make learners confused when pronouncing They are shown as follows:

1 /s/ - /ʃ/

2 /z/ - /ʒ/

3 /ʤ/ - /z/ or /s/

4 /ʧ/ - Vietnamese /ć/

As for the first pair, /ʃ/ is often pronounced as /s/ because either learners fail

to distinguish the difference between the two sounds or they are negatively affected

by their Hanoi dialect (/ʂ/ is pronounced as /s/) Regarding the second pair, with Hanoi dialect, many learners pronounce /ʒ/ as /z/ About the next pair, as mentioned above, the Vietnamese consonant system does not have any affricate consonant sounds; thus, many learners cannot pronounce the sound /ʤ/ They often change this sound into /z/ or /s/ The word judge /ʤʌʤ/, for instance, is pronounced as /zʌz/

or /zʌs/ When it comes to the last pair, English /ʧ/ is produced as Vietnamese /ć/, which is a voiceless palatal stop and is produced with the blade of the tongue touching the hard palate To illustrate, English /ʧ/ in child is incorrectly pronounced

as Vietnamese /ć/ in Vietnamese chai

In brief, regarding the six English consonants /s, z, ʃ, ʒ, ʤ, ʧ/, Vietnamese learners, especially those from the North of Vietnam have a tendency: (1) to change them into familiar sounds existing in their mother tongue (sound substitutions); (2)

to omit the sounds at the medial and final position (sound omission) This may make their English very Vietnamese but unintelligible, which, subsequently, may lead to many problems in communication with native speakers

I.8 Teacher’s Corrective Feedback

I.8.1 Definition of Teacher’s Corrective Feedback

In the literature of Second/Foreign Language Acquisition, one of the very first definitions of Teacher’s Corrective Feedback is offered by Chaudron (1977), who regards TCF as “any reaction of the teacher which clearly transforms, disapprovingly refers to, or demands improvement of the learner utterance.” Considering this definition, it seems that, according to Chaudron (1977), TCF means an evident and direct correction made by the teacher Nevertheless, as Hartono (2012) comments, TCF also involves providing learners with some clues to elicit their self-correction It can be seen that in Chaudron (1977) the term TCF is not be treated properly As a result, it is necessary to seek a more comprehensive definition of TCF The definition of TCF by Ellis, Loewen, and Erlam (2006, p.340) really comes in handy:

Corrective feedback takes the form of responses to learner utterances that contain error The responses can consist of (a) an indication that an error has been committed, (b) provision of the correct target language form, or (c) metalinguistic information about the nature of the error, or any combination

of these (Ellis, Loewen, & Erlam, 2006, p.340)

Ellis et al (2006) provides a clear picture of TCF that the researcher wants to mention First, it is oral corrective feedback, not written corrective feedback, which

is provided by the teacher Second, TCF can be simple, involving only one corrective strategy, or complex, involving a number of corrective moves The following example shows that the teacher uses two corrective feedback strategies,

which will be clarified in the next section, in an attempt to make the student generate a repair himself

Student: My mother bought me a new pair of shoes /suː/ on my fifteenth birthday Teacher: She bought you a new pair of… (Elicitation)

Student: Yes, a new pair of shoes /suː/…

Teacher: A new pair of shoes /ʃuːz/… really? (Recast)

Student: Ah yes, a new pair of shoes /ʃuːz/…

I.8.2 Types of Teacher’s Corrective Feedback

Lyster and Ranta (1997) carried out a study in several French immersion classrooms in Montreal The subjects were at primary level and their first language was English The researchers audio-taped four teachers whose lessons were transcribed These transcriptions provided database for their analyses After that, six main corrective feedback types, which later have widely been accepted by many studies, were explored

 Explicit correction means explicit provision of the correct form At the same time, the teacher clearly indicates that what the student said was incorrect and provides the correct form Sometimes the wrong form is identified along with the provision of the correct form in the teacher’s turn

E.g Student: Her shirt /sɜːt/is very dirty (Phonological error)

Teacher: No, you should say /ʃɜːt/ not /sɜːt/

without directly pointing out the student’s error

E.g Student: Her shop /sɒp/is very crowded (Phonological error)

Teacher: Yes, her /ʃɒp/is very crowded Where’s her /ʃɒp/?

Student: Her /sɒp/, ah, /ʃɒp/ is on Hue Street

 Clarification request is used in the form of questions like Pardon? and Sorry? to indicate that the learner’s utterance is not comprehensible Unlike

explicit correction and recast, this type of corrective feedback refers to the problems of comprehensibility

E.g Student: They boarded a ship /sɪp/ bound for India (Phonological error)

Teacher: Pardon?

Student: They boarded a /ʃɪp/ bound for India

 Metalinguistic feedback consists of either comments or information about how the student’s utterance is well-formed but the correct form is not explicitly provided It focuses on the nature of the error but attempts to elicit the information from the student

E.g Student: They boarded a ship /sɪp/ bound for India (Phonological error)

Teacher: Do we say /sɪp/?

Student: No, /ʃɪp/

 Elicitation refers to the technique used to directly elicit the correct form from the student The teacher can strategically pause to allow the student to fill in the blank in his/her utterance with the correct form Moreover, the teacher can directly ask the student to reformulate his/her utterance by saying

Say it again

E.g Student: They boarded a ship /sɪp/ bound for India (Phonological error)

Teacher: They boarded the…

Student: … /ʃɪp/ bound for India

 Repetition refers to the teacher’s repetition of the student’s error In most cases, the teacher adjusts his/her intonation in order to draw the student’s attention to the error

E.g Student: They boarded a ship /sɪp/ bound for India (Phonological error)

Teacher: /sɪp/? (rising tone) Student: /ʃɪp/

Lyster and Ranta’s research (1997) serves as a fundamental work in identifying different types of TCF in L2/FL classrooms Based on it, many studies have been conducted to examine which types of TCF are effective in improving L2/FL learning This issue is of great importance as it helps researchers answer the

question How should errors be treated? Once certain types of TCF are proved to be

more effective than the others, advices can be given to teachers in order to facilitate the process of error correction and better L2/FL learning There is also research work done in this trend but the six TCF types are grouped under antagonistic

categories: explicit and implicit

I.9 Teacher’s Explicit Corrective Feedback

There is a popular classification of TCF types, which is based on the implicitness or explicitness of a certain TCF strategy Let’s consider a situation

when a learner says, “Her shirt /sɜːt/is very dirty” If the response is “No, you should say /ʃɜːt/, not /sɜːt/”, it is called Explicit Corrective Feedback If the teacher

says, “Yes, her shop /ʃɒp/is very crowded”, her response is called Implicit Corrective Feedback It can be seen that in the case of Explicit Corrective Feedback, there is an overt indication that an error has been committed whereas in Implicit Corrective Feedback, the error is not directly shown According to Carroll and

Swain (1993) and Ellis, Loewen, and Erlam (2006), Teacher’s Explicit Corrective Feedback is often operationalized as explicit correction or metalinguistic feedback

recasts Clarification request, elicitation and repetition also fall into the category of TICF Metalinguistic feedback facilitates students’ self-repairs while error correction provides learners with correct reformulations and exemplars of the target

features In this study, the focus is on metalinguistic feedback as the researcher agrees with Swain (1985) who places an importance on students’ modified output rather than input (his viewpoint will be elaborated in section I.10.1) Furthermore, it should be noticed that the term TECF and metalinguistic feedback can be used interchangeably in this paper

Kenworthy (1987, p.1) comments:

If you’ve never seen a lime before you may think it is an unripe lemon because that is the nearest equivalent of the fruits you are familiar with You may continue in your misperception until you actually eat one or until someone points out the difference to you (Kenworthy, 1987, p.1)

In his opinion, students’ pronunciation mistakes may be fossilized if they do not receive any corrective feedback from their teacher Therefore, it is suggested that TCF plays an important role in L2/FL development Considering this classification of TCF, a question arises as to whether or not learners perceive the function of a certain TCF type as a correction when it is given explicitly/implicitly (Ding, 2012) In Loewen & Philp (2006, as cited in Ding, 2012), because of its implicitness, the corrective intention of recast may not be easily noticed by learners The following example indicates that the learner is likely to take the teacher’s recast

as a confirmation of what he/she said rather than a correction of his/her erroneous utterance Loewen & Philp (2006, as cited in Ding, 2012) argues that the teacher’s recast is not effective in helping learners notice the gap between their interlanguage and the target form, consequently leading to NO student reformulation not to mention student-generated repair In contrast, the corrective intention of TECF is more salient as it directly draws the learner’s attention to his pronunciation error

E.g Student: Her shop /sɒp/is near my house on Hue street (Phonological error)

Teacher: I see, her /ʃɒp/ is near your house… (Recast)

Student: Yes, and her /sɒp/is very crowded

However, there still exists another school of thought about TECF Bearing some doubt in mind about the effectiveness of TECF, Tornberg (2005, as cited in Lange, 2009) opines that TECF not only inhibits the students while communicating but also makes them uncomfortable If learners make a lot of pronunciation mistakes, TECF may intimidate their confidence in speaking Furthermore, Lange (2009), who also feels uncertain about the positive impact of TECF, argues that the utilization of this feedback type is time-consuming because the teacher has to wait long for students’ self-generated output

In fact, despite causing a lot of controversy, this classification of TCF has been of great interest to many researchers who are concerned about the role of input and output in L2 learning as well as the cognitive roles that TCF plays As the present study deals with TECF, in the next section, theoretical and empirical background that have boosted the research on TECF will be addressed in detail

I.10 Theoretical and Empirical Background on TECF

I.10.1 Theoretical Background on TECF

There has aroused much research in the role of input and output in L2/FL acquisition Krashen (1985) proposes the Input Hypothesis, which puts primary importance on the comprehensible input that language learners are exposed to According to him, acquisition occurs when learners understand input containing structures beyond the students’ current level of competence This means input can directly affect L2/FL learning Meanwhile, the Output Hypothesis is proposed by Swain (1985) based on her observation of the teaching and learning activities in French immersion classrooms The students in these classrooms were observed to have little difficulty in comprehending the teachers’ instruction; nevertheless, their production was often lack of accuracy As a result, she claims that the Comprehensible Input of Krashen (1985) alone was not sufficient for the development of learners’ language acquisition In her opinion, the production of output in response to input is necessary for further language development In other

words, Swain’s emphasis is on the role of modified output, which, according to her,

is important and necessary for L2 mastery Swain (1995) also recommended the use

of TCF because it stimulates learners to make more accurate and target-like output Considering error correction and metalinguistic feedback, it is only metalinguistic feedback that can stimulate learners to make more accurate and target-like output, creating opportunities for them to do output practices

Furthermore, the manner in which metalinguistic feedback contributes to the cognitive process of learners can support the theoretical claim that it plays an important role in facilitating the acquisition of new linguistic features According to Lyster (2004), the cognitive mechanism of L2/FL learning is described as an information-processing model, which refers to a gradual change from declarative to procedural knowledge (Anderson, 1983, as cited in Ding, 2012) Declarative knowledge refers to the knowledge of the language system while procedural knowledge refers to the knowledge about how to perform language accuracy, including language comprehension and production As regards language acquisition, there exist two types: (1) acquisition as the internalization of new forms, and (2) acquisition as an increase in control over forms that have already been internalized (Ellis, 1997, as cited in Ding, 2012) Therefore, it can be understood that the first type of language acquisition means the “acquisition of new declarative knowledge” and the second type means “the transition from declarative knowledge to procedural knowledge” (Ding, 2012) Based on Lyster’s view (2004),

it may be inferred that metalinguistic feedback which elicits target-like output can increase learners’ control over the already-internalized declarative knowledge, which promotes the transition from declarative knowledge to procedural knowledge Thus, TECF is supposed to play an important part in the cognitive process of L2/FL learning; however, this notion stills need support from empirical studies which examine the effect of TECF in facilitating L2/FL learning process

I.10.2 Empirical Background on TECF

Driven by the theoretical concerns discussed above, the effectiveness of TECF has become the subject of intensive inquiry The majority of previous studies addressing this issue were conducted within an experimental or quasi-experimental framework, by providing TECF and TICF as different treatments to different research groups, comparing the learning outcomes of these groups on a pre-test-post-test basis and attributing better learning outcomes to either TECF or TICF The advantage of this research design lies in the great accuracy it can bring about when examining the effects of TCF

There are a number of classroom studies that reported the advantage of TECF in helping learners achieve better learning outcomes on selected target linguistic features Spada and Lightbown (1993) demonstrated that TECF increased linguistic accuracy Most importantly, their results were maintained in a delay test five weeks after the treatment Hence, it can be seen that the effect of TECF can still

be present in the long term In White, Spada, Lightbown, and Ranta (1991), the performance of learners receiving TECF with those who did not receive this treatment was compared The result showed that the experimental group exposed to TECF showed a higher level of linguistic accuracy than the control group Furthermore, there were two studies conducted in 2004 showing the same results One was carried out by Lyster (2004) and the other by Rosa and Leow (2004) With regard to the design of two studies, the subjects were divided into three groups: (1) TICF in the form of recasts, (2) TECF, and (3) no TCF In Lyster (2004), the group receiving TECF outperformed the group exposed to recasts Both of the experimental groups outperformed the control group In Rosa and Leow (2004), the same result was produced Hence, the aforementioned studies demonstrate that TECF may be of pedagogical value (Ellis, Loewen & Erlam, 2006) Additionally, TECF is shown to be more effective than TICF (Carroll & Swan, 1993; Lyster, 2004; Ellis, Loewen & Erlam, 2006)

Though the above-mentioned studies do not specifically address pronunciation, their results are of great importance to pronunciation teaching They seem to suggest that the most effective TCF type can facilitate the acquisition of linguistic features If these results are taken into account in the case of pronunciation, there are reasons to believe that TECF will be an effective TCF type for pronunciation too

I.11 Research Gap

As a matter of fact, in Vietnam, a number of studies have been carried out to investigate the problems or difficulties that Vietnamese learners have in certain aspects of English pronunciation However, the cause-effect relationship between TECF and Vietnamese learners’ pronunciation is still a rather unexplored research area More specifically, little has been attempted to explore the cause-effect relationship between TECF and non-English major students’ pronunciation at DAV Additionally, there is little domestic research on this issue conducted within an experimental or quasi-experimental framework

Furthermore, according to Ding (2012), human behavior under study in social research is not “mechanistic” In her opinion, a social phenomenon like TECF can be understood if the human participants’ opinions, reactions, etc are taken into account It can be seen that little attention has been paid to experimental learners’ opinions about TECF they received, leaving a research gap in this area As

a result, further research in this direction is required

To address this major gap, the researcher has carried out a study on the impact of TECF on non-English major students’ pronunciation at DAV, the methodology of which will be elaborated in the coming chapter

CHAPTER II: METHODOLOGY

The following chapter will depict in detail the methodology of this research paper It includes the information about the context of the study, the study design, the selection of main participants, the procedures as well as the instruments for data collection and analysis

II.1 Context of the Study

The study was conducted at the Diplomatic Academy of Vietnam, which is located at 69 Chua Lang Street, Dong Da, Hanoi For the 2013-2014 academic year, the academy took in 450 undergraduate students in six disciplines of International Relations, International Law, International Economics, International Communication, English and French, and 60 college students in International Relations For students of Group A1 and D1, the standard point of enrollment in six disciplines ranged from 22 to 23.5 Thus, they can be assumed to have a certain threshold proficiency of English

On average, freshmen and sophomores spend about nine hours per week on learning English, which is divided into four sessions Each session lasts for 135 minutes and only focuses on one English skill

Generally, students at DAV are divided into two major groups, namely, English majors and non-English majors English majors refer to students who enroll

in the discipline of English and non-English majors are from five disciplines of International Relations, International Laws, International Economics and International Communication Both groups have to complete an English foundation course in the first three semesters In the fourth semester, there is a difference in the learning programs of two groups English majors have sessions of Phonetics, Grammar, Pragmatics, etc Meanwhile, non-English majors participate in the ESP programs

With regard to speaking skills, the teaching materials for non-English major freshmen are two books Let’s Talk 2 (used in the first semester) and Let’s Talk 3 (used in the second semester) These books include a variety of interesting and innovative topics that encourage students to develop their oral communication skills In Let’s Talk 2, an intermediate text, topics include relationships, jobs, sports and games, travel and transportation, the environment, arts and entertainment, and humor In Let’s Talk 3, a high-intermediate text, topics are related to communication, law, superstition, education, technology, etc There are review puzzles after every four units in order to help students recycle key vocabulary Activities are accompanied by full-color photographs and illustrations Nevertheless, it is noticed that there is no room for teaching pronunciation in the two books

It cannot be certain that students who sail through the university examination for group A1 and D1 are good at English pronunciation because the English test they take is in the form of a written one Furthermore, as mentioned in the first chapter, many non-English major freshmen at DAV are observed to make a lot of pronunciation mistakes when speaking; meanwhile, the teaching materials skip the English pronunciation part Therefore, it is necessary to improve their current situation of learning English in general and English pronunciation in particular

II.2 Study Design

To start with, there are some problems that the researcher had to take into consideration before choosing an appropriate design for this study:

First, random assignment to different groups is not always possible as it can

be done in a true experimental research In fact, it might be troublesome to ask for the mixture of different classes for the research purposes in a disciplined context as

my academy In fact, in education settings, the freedom of the researcher to manipulate and control the conditions under which the research is conducted is often restricted (Seliger and Shohamy, 1989) The administrators are generally

unwilling to allow classes to be reorganized since it may be unfavorable for the ongoing programs Even if the researcher could mix up different classes, the true experimental approach would not be a wise choice The learners have the right to know what is happening with them (i.e., reorganization of classes are necessary for conducting the research) but the findings may be harmed actually (McDonough and McDonough, 1997) Last but not least, the students are likely to be reluctant to cooperate with the researcher in a true experiment because they may think that it will interfere in their learning routines and affect their academic outcomes

Of course, the researcher can choose two intact classes for comparison but this nonequivalent comparison group design appears a threat to the internal validity, especially in the researcher’s situation In that semester, the researcher was assigned

to teach two classes, KT40B and CĐ05B (university level and junior college level respectively), whose academic achievement levels were assumed not to be equal Furthermore, junior college students are not the focus of the study As Johnson & Christensen (2007) comments, “any factor that the treatment and control groups differ on are potentially confounding variables that threaten our ability to attribute group differences after the intervention to a treatment effect” However, the class assignment at DAV was not the researcher’s rights As a result, the researcher decided not to conduct her study on two intact classes In other words, the researcher had no alternative but to choose the class KT40B as the sample of the study

To overcome the aforementioned inconvenience, the researcher decided to choose the following quasi-experimental design:

First, a pre-test was administered to 36 students in the class KT40B for three purposes:

 To select the main subjects of the study To be specific, the subjects having much lower or higher scores than the rest of subjects (in statistics, they are called “outliers”) would be ruled out from the sample In other words, the main subjects, who later were assigned to the experimental and control

group, were roughly at the same pronunciation level of English alveolar fricatives, alveo-palatal fricatives and affricates How the main subjects were selected will be clarified in the Section II.3

 To assign the subjects to the experimental and control group The procedure

of group assignment will be presented in the Section II.4

 To compare with the post-test to find out the answer to the first research question

As regards the written part of the pre-test, the students’ answers were marked

by two Vietnamese teachers When it comes to the sound production part of the test, the performance of each student was recorded and checked by two native English teachers to get the final score

pre-After that, in ten weeks, the intervention (TECF) was administered to the experimental group whereas there was no intervention in the control group How the two groups were treated will be explained in the Section II.7

Finally, after ten weeks, both groups sat for a post-test whose structure was similar to that in the pre-test The method of scoring is also the same The pre-test and post-test scores of both groups were used for comparison so that the answer to the first research question can be found

Besides, a short written questionnaire was used as the supplementary instrument to explore the experimental students’ evaluative opinions about TECF after the experiment period

This quasi-experimental design is feasible for the researcher to conduct the present study The results of the study were presented in numerical expression (e.g., test scores) and then analyzed by trustworthy and powerful statistical computer software To be specific, in this study, the link between the pre-test and post-test scores of both groups was brought to light by paired-samples t-test with the assistance of the computer software SPSS version 16.0 (Statistical Package for Social Science), which is widely-used for statistical analysis