Effects Of Task Types And Vocabulary Sizes On Incidental Vocabulary Acquisition Of Senior High School Students

Incidental Vocabulary Acquisition(IVA)refers to the learning of vocabulary as a by-product of other activities that are not explicitly geared to lexical learning.Although learners' attention is not directly related to target words,they can acquire words in an incidental way.IVA can be affected by reading materials,task types and learners' own factors.A large number of previous studies have proven that the involvement loads and learners' L2 proficiency are significantly effective to IVA.Given that summary writing is a newly popular task in recent years,it is rarely analyzed before.Also,the specific influence of vocabulary sizes on IVA lacks further discussion,so the current study aims to answer the following three questions: 1)How do task types influence the immediate and delayed effects on IVA of senior high students? 2)How do vocabulary sizes influence the immediate and delayed effects on IVA of senior high students? 3)Do task types and vocabulary sizes have interactive effects on IVA?To answer the questions above,ninety students of Grade Two from a senior high school in Nanjing were selected as participants.In the pretest,they were required to complete the Vocabulary Size Test(VST).Based on their scores,they were assigned to three different vocabulary groups,that is Group Large,Group Medium and Group Small.Each group had 30 students.Subsequently,three task groups with the same number of participants and relatively similar vocabulary level were formed by selecting students from each vocabulary group randomly.After reading a same article,they were assigned with different tasks.Task 1 was to translate sentences containing target words in the article into Chinese.Task 2 was to make original sentences with target words.And Task 3 was to write a summary of the article with target words.Based on the Involvement Load Hypothesis(ILH),the involvement index of each task was 2,3 and 3 respectively.Then,the Vocabulary Knowledge Scale(VKS)was applied in the immediate post-test and delayed post-test(one week later).Nine students with different vocabulary sizes were involved in the interview.Results showed that: 1)Tasks with higher involvement loads result in bettereffects on IVA.To be more specific,sentence making and summary writing are superior to English-Chinese translation.Although there is no significant difference between these two tasks,the means of summary writing are slightly higher both in the immediate and delayed post-tests.2)Larger vocabulary sizes lead to better word retention.But there is no significant difference between Group Large and Group Medium.3)Task types and students' vocabulary sizes have no significant interactive effects on IVA.In the immediate test,task types and vocabulary sizes exert similar influence.As for the delayed test,the influence of vocabulary sizes is slightly greater.Therefore,the findings suggest that: 1)The theory of ILH still remains to be improved.2)Teachers should select appropriate reading materials,design appropriate reading tasks,and encourage students to read extensively so as to consolidate new words.Summary writing has significant impacts on IVA,so greater importance should be attached to this task.3)For students with large and medium vocabulary sizes,sentence making and summary writing achieve similar effects.For low-level students,sentence making is a preferable choice.4)Compared with reading tasks,learners' vocabulary sizes exert greater influence on IVA in the long term,so incidental and intentional vocabulary learning methods should be properly combined in order to improve students' vocabulary knowledge.