500 likes | 617 Views
An Experimental study of Task-based L2 lexical Learning by Chinese EFL learners Zhou Weijing School of Foreign Languages Jiangsu University.
E N D
An Experimental study of Task-based L2 lexical Learning by Chinese EFL learners Zhou Weijing School of Foreign Languages Jiangsu University
An Experimental Study of Task-based L2 Lexical Learning by Chinese EFL Learners Outline • Introduction • Literature review • Methodology • Major findings and discussions • Contributions & Limitations
Introduction • Motivation of the study • Need for the study • Orientation of the study
Introduction 1. Motivation • Vocabulary plays a central role in L2 learning and teaching, however, L2 teachers are often unsure about how best to incorporate L2 vocabulary into their daily teaching. pedagogical requirements for efficient L2 teaching • Pedagogical vexation results from theoretical inadequacy. (Read,2004). Although there’s been a boom in L2 vocabulary studies since 1990s, the mechanism of L2 lexical learning remains one of the most intriguing puzzles in SLA (Reed, 2004). theoretical urge for sound understanding of L2 lexical learning • Personally, being an L2 teacher and researcher, I have been impelled to do research on L2 lexical learning. personal experience of L2 lexical learning and teaching
Introduction 2. Need for the study Despite increasing interest and efforts in L2 vocabulary in the past 10 years, basic issues remain unsolved. • How do L2 learners acquire L2 lexicon? • How do L2 learners acquire new vocabulary via learning tasks? • What factors affect L2 lexical learning in or outside classroom? • How to tract L2 learners’ incremental lexical learning? Consequently, our knowledge of L2 lexical learning has mainly been built upon fragmental studies and there isn’t an overall theory of how L2 vocabulary is acquired (Schimitt, 1998, Read, 2004). Crying need to explore L2 lexical learning, theoretically, pedagogically, and methodologically.
Introduction 3. Orientation of the study Handicaps hindering the studies up to date : • No consistent or inclusive definition of the basic unit of L2 vocabulary, which makes the research domain a tricky and muddy area to explore. • No solid evidence for an efficient way to enhance L2 learners’ lexical knowledge, in addition to controversies over incidental and intentional L2 approaches. • Task-based L2 lexical learning seems to be an optimal area to investigate L2 lexical learning. Nevertheless, there is far from sufficient understanding of task-based L2 lexical learning according to the literature to date. • Lopsided focus of present-day research on L2 lexical vocabulary learning. • Inadequate support, either theoretically or empirically, for the Involvement Load Hypothesis (Laufer and Hulstijn, 2001), the newly-born theoretical construct targeting at L2 lexical learning. • Besides word-based factors, few studies explored learner-related factors
Literature review • Key terms • Theoretical framework • Previous empirical findings
Literature review • Key terms ---To get rid of problems of ‘word’ and ‘word familiar’, the present study adopted lexical unit (LU) as the basic unit of L2 vocabulary covering single words and multi-word chunks and idioms.
Literature review • Theoretical framework • Input Hypothesis(Krashen, 1985,1989) • Output Hypothesis(Swain,1985, 1995) • Nation’s (2001) construct of L2 lexical knowledge 3 aspects: form, meaning, usage 2 levels: receptive & productive • Involvement Load Hypothesis (Laufer & Hulstijn, 2001 ) ---the latest and sole theoretical construct ---targeting at L2 lexical learning.
What is involved in knowing a word • FormSpoken R What does the word sound like? P How is the word pronounced? Written R What does the word look like? P How is the word written and spelled? word parts R What parts are recognizable in this word? P How word parts are needed to express the meaning? • Meaning Form & meaning R What meaning does this word form signal? P What word form can be used to express this meaning? Concept & referents R What is included in the concept? P What items can the concept refer to? Associations R What other words does the word occur? P What other words could we use instead of this one? • Use Grammatical functions R In what patterns does the word occur? P In what patterns must we use this word? Collocations R What words or types of words occur with this one? P What words or types of words must we use with this one? Constraints on use R Where, when, and how often would we expect to meet this word? P Where, when, and how often can we use this word?
Involvement Load Hypothesis(Laufer & Hulstijn, 2001 ) • Its basic contention : --- The retention of unfamiliar words is, generally, conditional upon the degree of involvement in processing these words.
Involvement Load Hypothesis(Laufer & Hulstijn, 2001 ) • Its 3 assumptions : • Retention of words, when processed incidentally, is conditional upon the following factors in a task: need, search and evaluation. • Other factors being equal, words which are processed with higher involvement load will be retained better than words which are processed with lower involvement load. • Other factors being equal, teacher/researcher-designed tasks with higher involvement load will be more effective for vocabulary retention than tasks with a lower involvement load. • Task-induced involvement does not have much to do with whether it is an input or output task.
Involvement Load Hypothesis(Laufer & Hulstijn, 2001 ) • Motivational-cognitive construct of involvement:need, search & evaluation. • L2 lexical learning is conditional upon task-induced involvement. • The higher involvement, the better acquisition and longer retention of unknown words.
Literature review • Empirical findings • Majority: looking for evidence for task-based L2 lexical learning A few: on effects of task type. Few: on effects of task frequency, word and learner factors indicating: task type, task frequency, word and text factorsas well as learner factorsaffect L2 lexical learning Reading-based complex tasks : the most facilitative for L2 lexical learning. • Involvement Load Hypothesis: only partially supported. 1) Motivational-cognitive construct : problematic. 2) Involvement Load Hypothesis : needs further rectification.
Methodology Based on previous studies, an experimental study of task-based L2 lexical learning was designed and conducted.
Methodology • Research Questions How do Chinese EFL learners acquire L2 vocabulary through learning tasks? 1. Effects of task type on L2 lexical learning? • Overall effects • Modify effects • Role of task-induced involvement 2. Effects of task frequency on L2 lexical learning? - Overall effects - Modified effects - Optimal task frequency 3. Effects of lexical presentation on L2 lexical learning? - Overall effects - Modified effects - Most or least acquired LUs? Why?
Design Pretest-posttest experimental design • TASK-BASED FACTORS • Task type • Task frequency • Lexical presentation • …… Task-based L2 Lexical learning Read silently + comprehension Read aloud + comprehension Read silently + reproduction Read aloud + reproduction First exposure Second exposure Third exposure • LEARNER-BASED FACTORS • English proficiency • Prior lexical knowledge …… Lexical formation Contextualelaboration Notes: refers to the effects of independent variable on dependent variable refers to the effects of moderator variable on dependent variable
Methodology • Subjects • 4 EGs: 119 English majors (EG 1/2/3:30; EG 4: 29) • Homogenous in age, learning background, motivation. • Pretests: No significant differences between 4 EGs in 1. English proficiency 2. vocabulary size, and 3. baseline knowledge of target LUs.
Methodology • Material A treatment text • Length: 411 words • No of target LUs: 21 • Coverage of known LU: 95%
Methodology • Instruments
Methodology Data collection and analysis Data collection: in a language lab Data analysis: 1. Revised 9-scale scoring of VKS (Wesche & Paribakht, 1996: 5-scale scoring) 2. Statistic software: SPSS
III. VKS & its 5-point scoring • VKS elicitation scale(Wesche & Paribakht, 1996) Self-report categories I. I don’t remember having seen this word just now. II. I have seen this word just now, but I don’t know what it means. III. I have seen this word just now, and I think it means____________ (synonym or translation). IV. I know this word. It means _______________ (synonym or translation). V. I can use this word in a sentence: _____________________________ ( If you do this section, please do section VI).
VKS Scoring (Wesche & Paribakht, 1993), Self-report possible Categories scores Meaning of scores • I. 1 This word is not familiar at all. • II. 2 The word is familiar but the meaning is not known. • III. 3 A correct synonym or translation is given. • IV. 4 The word is used with semantic appropriate in a sentence. • V. 5 The word is used with semantic appropriateness and grammatical accuracy in sentence
Major findings & discussions • Effects of task type • Effects of task frequency • Effects of lexical presentations
Findings &discussions • Effects of task type Conclusions 1. The facilitative power of each task varied significantly from one another. 2. RS+R was the most facilitative and RA+R was the least helpful. Task type significantly affects L2 lexical learning.
Modified effects of task type Learning outcomes after the 1st exposure Findings &discussions Conclusion
Modified effects of task type Average learning outcomes after 3 exposures Findings &discussions
Modified effects of task type • To conclude, the overall effects of task type were generally modified by English proficiency in the 4 EGs’ lexical learning. To be specific, • HL: achieved similar lexical progress, regardless of the significant different effects of task type; • ML : abided by the effects of task type to the letter; and • LL : being unable to make full use of the effects of task type, keeping their lexical learning at a similar low rate. Findings &discussions
Findings &discussions • Effects of task type • 2. Modified effects • Each EG: 3 subgroups according to their English proficiency (HL, ML, LL). • Significant correlations between English proficiency and L2 lexical learning outcomes. ( 1st: r=.352***; Average 1-3: r=.456***) • Overall effects of task type : ---- totally rejected by HL, ----strictly followed by ML ---- abided by at the first trial and refuted at the later trials by LL. Conclusion Overall effects of task type were generally modified by English proficiency. • . • Conclusion:
Findings &discussions • Role of task-induced involvement Involvement loads of the 4 tasks according to motivational-cognitive construct of task-induced involvement (Laufer & Hulstijn,2001) Prediction: No significant differences between EG1 and EG2 / between EG1 and EG2 Significant differences between EG(1+2) and EG(3+4)
Findings &discussions • Role of task-induced involvement Predicted rank order of learning outcomes Actual rank order of learning outcomes
Findings &discussions • Effects of task type • 3. Roles of task-induced involvement • Motivational-cognitive construct of involvement : theoretically invalid task-based construct • Involvement Load Hypothesis : partially supported. Optimal involvement Load Hypothesis 1)Tasks vary in their involvement: under-involving, optimal, and over-involving 2) Productive tasks are usually more involving than receptive ones. 3) Tasks with balanced integration of input and output are endowed with optimal involvement, resulting best learning outcomes.
Findings & discussions 1. Which task most facilitates L2VA? RS+R >/≈RA+C > RA+R>RS+C 1. Both input and output are essential to L2VA. 2. Neither mere input nor overproduction facilitates high gains in L2VA. 3. Optimal involvement is required for L2VA. Optimal involved Under-involved Over- involved
Findings &discussions • Role of task-induced involvement Results of Independent Samples T-Tests • Indications • Involvement load Hypothesis: partially supported, partially rejected. • Motivation-cognitive construct: problematic • equal value for need, search, evaluation • exclusion of input-output dimension
Findings &discussions Task-based construct of involvement • Motivational-cognitive • Input-output
Findings &discussions • Effects of task frequency • Overall effects • Task frequency significantly affected the 4 EGs’ lexical learning and the third trial led to the most progress. • Task frequency had the power to reduce involvement loadand the gaps caused by the effects of task type, but the modifying effects can not override the effects of task type • Task frequency interacted with task type.
Tests of Within-Subjects Contrasts in regards to HL, ML and LL’s lexical learning outcomes after each exposure
LL ML HL
Findings &discussions • Effects of task frequency 2. Modified effects • HL: no variation between subgroups: fully enjoying the overall effects • ML: variations enlarged at the 2nd trial but narrowed at the third trial. • LL: variations revealed at the 2nd trial but vanished at the third trial. 3. Optimal task frequency • The 3rd exposure.
Findings &discussions • Effects of lexical presentation • Overall effects • Lexical formation and contextual elaborations significantly affected 4 EGs’ lexical learning. 1) Multi-word LUs were better learnt than single-word LUs. 2) Both implicit and explicit elaborated LUs were better learned than no elaborated ones. • Lexical formation and contextual elaborations not only interwove with each other, but also interrelated with, or controlled by learners’ prior lexical knowledge
Findings &discussions • Effects of lexical presentation 2. Modified effects • HL had the greatest achievements than ML and LL in the 2 types of presented LUs. • HL and ML achieved more gains in implicitly elaborated LUs, whereas LL had more progress in explicitly elaborated LU. 3. Most and least acquired LUs • Familiarity with the LU form and implicit/explicit elaborations led to the most acquired LUs, and vice versa. • Ignorance of word parts, high density of target LUs and mutual antonyms of LUs also lead to least acquired LUs.
Contributions & limitations • Contributions Theoretical • Modifying the motivational-cognitive construct of task-induced involvement and Involvement Load Hypothesis • Clarifying the role of input and output in task-based L2 lexical learning. • Revealing the complexity of task-based L2 lexical learning. Methodological • Combining quantitative and qualitative methods in L2 lexical research. • Devising more valid scoring of VKS Pedagogically • Applying the effects of task type, task frequency, word and text factors as well as learner factors in L2 lexical teaching.
Task type • Learner factors • English proficiency • Prior lexical knowledge Task frequency • Lexical presentation • formation • elaboration Task-based L2 learning
Contributions & limitations 2. Limitations • Three trials of tasks may not enough for the effects of task frequency. • The effects of vocabulary acquisition tests should be teased out from the effects of task frequency.