1、 An Experimental study of Task-based L2 lexical Learning by Chinese EFL learners Zhou Weijing School of Foreign Languages Jiangsu University Outlinel Introduction l Literature reviewl Methodologyl Major findings and discussionsl Contributions&LimitationslMotivation of the studylNeed for the studylOr
2、ientation of the study1.Motivation lVocabulary 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 teachinglPedagogical vexation results from theoretical
3、inadequacy.(Read,2004).Although theres 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 lPersonally,being an L2 teacher and researcher,I h
4、ave been impelled to do research on L2 lexical learning.personal experience of L2 lexical learning and teaching 2.Need for the study Despite increasing interest and efforts in L2 vocabulary in the past 10 years,basic issues remain unsolved.lHow do L2 learners acquire L2 lexicon?lHow do L2 learners a
5、cquire new vocabulary via learning tasks?lWhat factors affect L2 lexical learning in or outside classroom?lHow to tract L2 learners incremental lexical learning?Consequently,our knowledge of L2 lexical learning has mainly been built upon fragmental studies and there isnt an overall theory of how L2
6、vocabulary is acquired(Schimitt,1998,Read,2004).Crying need to explore L2 lexical learning,theoretically,pedagogically,and methodologically.3.Orientation of the study Handicaps hindering the studies up to date:lNo consistent or inclusive definition of the basic unit of L2 vocabulary,which makes the
7、research domain a tricky and muddy area to explore.lNo solid evidence for an efficient way to enhance L2 learners lexical knowledge,in addition to controversies over incidental and intentional L2 approaches.lTask-based L2 lexical learning seems to be an optimal area to investigate L2 lexical learnin
8、g.Nevertheless,there is far from sufficient understanding of task-based L2 lexical learning according to the literature to date.lLopsided focus of present-day research on L2 lexical vocabulary learning.l Inadequate support,either theoretically or empirically,for the Involvement Load Hypothesis(Laufe
9、r and Hulstijn,2001),the newly-born theoretical construct targeting at L2 lexical learning.lBesides word-based factors,few studies explored learner-related factors uKey termsuTheoretical frameworkuPrevious empirical findings vKey terms -To get rid of problems of word and word familiar,the present st
10、udy adopted lexical unit(LU)as the basic unit of L2 vocabulary covering single words and multi-word chunks and idioms.vTheoretical frameworkuInput Hypothesis(Krashen,1985,1989)uOutput Hypothesis(Swain,1985,1995)uNations(2001)construct of L2 lexical knowledge 3 aspects:form,meaning,usage 2 levels:rec
11、eptive&productive uInvolvement Load Hypothesis(Laufer&Hulstijn,2001)-the latest and sole theoretical construct -targeting at L2 lexical learning.What is involved in knowing a wordlForm Spoken R What does the word sound like?P How is the word pronounced?Written R What does the word look like?P How is
12、 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?lMeaning 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 conc
13、ept?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?lUse 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 occ
14、ur 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?lIts basic contention:-The retention of unfamiliar words is,generally,conditional upon the degree
15、of involvement in processing these words.lIts 3 assumptions:lRetention of words,when processed incidentally,is conditional upon the following factors in a task:need,search and evaluation.lOther factors being equal,words which are processed with higher involvement load will be retained better than wo
16、rds which are processed with lower involvement load.lOther 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.lTask-induced involvement does not have much to do with whether it is
17、 an input or output task.l Motivational-cognitive construct of involvement:need,search&evaluation.lL2 lexical learning is conditional upon task-induced involvement.lThe higher involvement,the better acquisition and longer retention of unknown words.v Empirical findingsuMajority:looking for evidence
18、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 factors as well as learner factors affect L2 lexical learning Reading-based complex tasks:the most facilitative for L2 lexical
19、learning.uInvolvement Load Hypothesis:only partially supported.1)Motivational-cognitive construct:problematic.2)Involvement Load Hypothesis:needs further rectification.Based on previous studies,an experimentalstudy of task-based L2 lexical learning was designed and conducted.v Research Questions How
20、 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 involvement2.Effects of task frequency on L2 lexical learning?-Overall effects -Modified effects -Optimal task frequency 3.Effects
21、of lexical presentation on L2 lexical learning?-Overall effects -Modified effects -Most or least acquired LUs?Why?TASK-BASED FACTORS l Task type lTask frequency lLexical presentation LEARNER-BASED FACTORS lEnglish proficiencylPrior lexical knowledgeTask-basedL2 Lexical learningRead silently+comprehe
22、nsionRead aloud +comprehensionRead silently+reproductionRead aloud +reproductionFirst exposureSecond exposureThird exposureLexical formationContextual elaborationl DesignPretest-posttest experimental design Notes:refers to the effects of independent variable on dependent variable refers to the effec
23、ts of moderator variable on dependent variable vSubjectsu4 EGs:119 English majors (EG 1/2/3:30;EG 4:29)uHomogenous in age,learning background,motivation.uPretests:No significant differences between 4 EGs in 1.English proficiency 2.vocabulary size,and 3.baseline knowledge of target LUs.vMaterial A tr
24、eatment text uLength:411 words uNo of target LUs:21uCoverage of known LU:95%vInstruments PretestExperimentPosttest4 weeks before1 afternoonAfter the experiment1.TEM-42.V size test3.Spelling test of target LUs4 tasks EG1:(RS+C)3EG2:(RA+C)3EG3:(RS+R)3EG4:(RA+R)31.V acquisition test32.Spelling test of
25、target LUs3.InterviewsData collection:in a language labData analysis:1.Revised 9-scale scoring of VKS (Wesche&Paribakht,1996:5-scale scoring)2.Statistic software:SPSSlVKS elicitation scale(Wesche&Paribakht,1996)Self-report categoriesI.I dont remember having seen this word just now.II.I have seen thi
26、s word just now,but I dont 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).Self-report possible Categories
27、scores Meaning of scoreslI.1 This word is not familiar at all.lII.2 The word is familiar but the meaning is not known.lIII.3 A correct synonym or translation is given.lIV.4 The word is used with semantic appropriate in a sentence.l V.5 The word is used with semantic appropriateness and grammatical a
28、ccuracy in sentence stagescoringschemeF10Not familiar at all21Familiar with the form+no/wrong meaning is given 31.5Familiar with the form+no/wrong meaning+copy of the original sentenceM42Similar sense 52.5Similar sense+original/creative sentence63Right sense73-0.5Right sense+grammatical error in sem
29、antic presentationU84Right sense+copy of the original sentence/creative sentence with grammatical error95Right sense+correct creative sentence wEffects of task typewEffects of task frequencywEffects of lexical presentationsConclusions 1.The facilitative power of each task varied significantly from o
30、ne another.2.RS+R was the most facilitative and RA+R was the least helpful.Task type significantly affects L2 lexical learning.Conclusion Englishproficiency LevelSubgroupsNMeanSDMini Max Between-subgroup(Kruskal-Wallis)Chi-squareAsymp.Sig.HLEG1(RS+C)1041.109.6029.5059.501.303.728EG2(RA+C)1045.107.16
31、34.5056.00EG3(RS+R)1045.2516.2824.0071.00EG4(RA+R)1040.709.5429.0054.50Total4043.0410.9524.0071.00MLEG1(RS+C)1030.505.8818.0036.5016.390.001EG2(RA+C)1043.909.2827.5059.50EG3(RS+R)1047.8510.1531.0065.50EG4(RA+R)937.459.3222.0050.50Total3939.9210.7818.0065.50LLEG1(RS+C)1028.456.0119.0036.509.760.021EG
32、2(RA+C)1037.856.3028.5051.00EG3(RS+R)1039.9510.1526.0060.00EG4(RA+R)1036.504.4530.0046.00Total4035.678.1519.0060.00 Englishproficiency LevelSubgroupsNMeanSDMini Max Between-subgroup(Kruskal-Wallis)Chi-squareAsymp.Sig.HLEG1(RS+C)1054.109.2536.8370.67.579.901EG2(RA+C)1055.2316.2025.8375.50EG3(RS+R)105
33、7.258.4142.8368.83EG4(RA+R)1055.018.4442.1766.83Total4055.3910.6925.8375.50MLEG1(RS+C)1037.637.9926.0046.8319.023.000EG2(RA+C)1054.3010.3639.5072.17EG3(RS+R)1061.469.2743.6775.67EG4(RA+R)945.948.8433.6758.17Total3949.9412.6926.0075.67LLEG1(RS+C)1037.169.3922.5048.834.768.190EG2(RA+C)1046.1610.3038.0
34、067.67EG3(RS+R)1049.1812.8134.0073.00EG4(RA+R)1042.916.6834.6753.67Total4043.8510.6522.5073.00 2.Modified effectsEach EG:3 subgroups according to their English proficiency(HL,ML,LL).lSignificant correlations between English proficiency and L2 lexical learning outcomes.(1st:r=.352*;Average 1-3:r=.456
35、*)lOverall 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.ConclusionOverall effects of task type were generally modified by English proficiency.Conclusion:Prediction:No significant differences between EG1 and
36、EG2/between EG1 and EG2 Significant differences between EG(1+2)and EG(3+4)SubjectsTasksInvolvement loadInvolvement IndexRank orderof learning outcomesNeedSearchEvaluationEG1RS+C+_24thEG2RA+C+_22ndEG3 RS+R+41stEG4RA+R+43rd Predicted rank order of learning outcomes Actual rank order of learning outcom
37、es3.Roles of task-induced involvementlMotivational-cognitive construct of involvement:theoretically invalid task-based construct lInvolvement Load Hypothesis:partially supported.Optimal involvement Load Hypothesis 1)Tasks vary in their involvement:under-involving,optimal,and over-involving 2)Product
38、ive 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.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 inp
39、ut nor overproduction facilitates high gains in L2VA.3.Optimal involvement is required for L2VA.Optimal involvedOver-involvedUnder-involvedIndications1.Involvement load Hypothesis:partially supported,partially rejected.2.Motivation-cognitive construct:problematiclequal value for need,search,evaluati
40、onlexclusion of input-output dimensionResults of Independent Samples T-TestsF Sig.t df Sig.(2-tailed)EG1-EG2.001.974-4.0258.000EG3-EG46.16.0162.1957.032EG（1+2）-EG（3+4）1.46.22-1.87117.063SubjectsTasksInvolvement loadInvolvement IndexNeedSearchEvaluationEG1RS+C+n+s+e4EG2RA+C+n+s+e7EG3 RS+R+n+s+e8EG4RA
41、+R+n+s+e10uMotivational-cognitiveuInput-output 1.Overall effectslTask frequency significantly affected the 4 EGs lexical learning and the third trial led to the most progress.lTask frequency had the power to reduce involvement load and the gaps caused by the effects of task type,but the modifying ef
42、fects can not override the effects of task typelTask frequency interacted with task type.Tests of Within-Subjects Contrasts in regards to HL,ML and LLs lexical learning outcomes after each exposureSubgroupSourceTask frequencyType III Sum of SquaresdfMean SquareFSig.HLTask frequencyRun 1 vs.Run 27581
43、.7617581.76118.09.000Run 2 vs.Run 35017.6015017.60104.65.000MLTask frequencyRun 1 vs.Run 24995.2214995.22146.28.000Run 2 vs.Run 32480.6212480.6252.14.000LLTask frequencyRun 1 vs.Run 22600.1512600.1533.59.000Run 2 vs.Run 31939.0511939.0550.57.000HL ML LL 2.Modified effectslHL:no variation between sub
44、groups:fully enjoying the overall effectslML:variations enlarged at the 2nd trial but narrowed at the third trial.lLL:variations revealed at the 2nd trial but vanished at the third trial.3.Optimal task frequencylThe 3rd exposure.1.Overall effects l Lexical formation and contextual elaborations signi
45、ficantly 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.l Lexical formation and contextual elaborations not only interwove with each other,but also interrelated with,or c
46、ontrolled by learners prior lexical knowledge 2.Modified effects l HL had the greatest achievements than ML and LL in the 2 types of presented LUs.l HL and ML achieved more gains in implicitly elaborated LUs,whereas LL had more progress in explicitly elaborated LU.3.Most and least acquired LUsl Fami
47、liarity with the LU form and implicit/explicit elaborations led to the most acquired LUs,and vice versa.l Ignorance of word parts,high density of target LUs and mutual antonyms of LUs also lead to least acquired LUs.Task-based L2 learningTask type Task frequencyLearner factorsl English proficiencylPrior lexical knowledgeLexical presentationl formationl elaboration Questions and suggestions!Thanks You!Thanks You!
