Effects Of Different Types Of Medium Of Instruction On The Second Language Vocabulary Acquisition Of Senior High School Students

Vocabulary is the foundation of a language,and vocabulary acquisition is an indispensable part of language learning.In China,most of the senior high school students are learning English as a foreign language,and classroom is the major place for them to learn English.Therefore,vocabulary teaching in instructional settings plays a vital role in senior high school students' English study.However,there is few empirical research aiming to investigate factors which may have influence on the development of lexical knowledge of senior high school students.Based on previous studies,the purpose of this study was to examine effects of different types of medium of instruction(MoI),i.e.through which language knowledge is taught in the classroom setting,in English vocabulary teaching on senior high school students' learning and retention of lexical knowledge.In this study,adopting the quasi-experimental method,the subjects were senior one students of two parallel classes from The High School Attached To Hunan Normal University,who were learning English in classrooms.This study mainly used the Revised Hierarchical Model,L2 Lexical Representation and Development Model,Mental Lexicon and Ebbinghaus Forgetting Curve as the theoretical basis.Before the intervention,a vocabulary size test was conducted on all the subjects,used to screen the subjects to ensure that there was no significant difference between the vocabulary proficiency of all the participating students in the experiment.The selected subjects were divided into two groups,one is first language(L1)group,in which L1 was used by the teacher to interpret the target vocabulary,and the other second language(L2)group,in which the teacher would use L2 as the MoI in vocabulary teaching.The results showed that:(1)On the whole,the results suggested that the effect of the use of L1 as the MoI was superior to that of using L2 on the learning of the lexical knowledge of senior high school students,who were less proficient L2 learners.It need to be noted that when it comes to productive vocabulary knowledge of orthography,L1 group outperformed L2 group,while there was no statistically significant difference between them,indicating that the impacts of the two types of MoI on the learning of productive orthographic vocabulary knowledge were approximate.(2)As for the retention outcome,the effect of using L1 as the MoI preceded that of using L2 as the MoI on all aspects of lexical knowledge that were tested.The results mainly implied that teachers' use of L1 as MoI in L2 vocabulary teaching classes in senior high schools is conducive to students' acquisition of vocabulary knowledge,but at the same time,we should not ignore the possibly adverse impact of students' dependence on L1 on L2 vocabulary acquisition.In addition,the present study pointed out that teachers should guide and urge students to review vocabulary knowledge in a scientific and effective way after class to improve the retention of vocabulary knowledge.