A Study Of Lexical Richness In English Writing By Senior High School Students

Lexical richness can not only measure the development of vocabulary,but also effectively assess the quality of second language writing.Recently,a large amount of research at home and abroad has focused on lexical richness,which,however,are mostly cross-sectional in design and mainly centre on the development of advanced second language learners in different dimensions.Meanwhile,most comparative studies focus on the differences between English native speakers and foreigners,ignoring Chinese English learners with different language proficiency.Besides,results of the relationship between lexical richness and writing quality turn out to be quite controversial.Therefore,a mixture of longitudinal and cross-sectional study was conducted,the former trying to explore the development of lexical richness in second language writing of senior high school students from four dimensions,including lexical variation,lexical sophistication,lexical density and lexical errors,while the latter aiming to discover the differences between the characteristics in lexical richness of the senior high school students with different language proficiency and the relationship between the senior high school students' lexical richness and their L2 writing performance.Guided by the Interlanguage Theory,Input and Output Hypotheses and Dynamic System Theories,this study mainly addressed three questions:(1)What are the general features of the development of lexical richness in English writing by senior high school students?(2)What are the differences between the characteristics in lexical richness of the senior high school students with different levels of language proficiency?(3)What is the relationship between the senior high school students' lexical richness and their L2 writing performance?The online software Vocabprofile was adopted to analyze the lexical development of 288 timed compositions of 36 senior high school students collected during two years.The data were then submitted to SPSS 23.0 for further analysis,yielding the following findings:1)Generally,a nonlinear developmental pattern of the lexical richness was discovered,indicated by an upward trend in the development of the lexical variation,lexical sophistication and lexical density,with peaks and valleys existing in the development of lexical richness,but a downward trend in lexical errors.This showed that although the development of lexical richness has stagnated from time to time,the overall trend was still dynamically growing.2)A significant difference was found in terms of lexical errors between students with different levels of language proficiency,while there was not a remarkable difference of the other three dimensions.Avoidance strategies adopted by high-level learners,restricted use of vocabulary due to the same topic and genre of compositions,and lack of validity of lexical density attributed to the insignificant differences.3)Different dimensions of lexical richness have imbalanced impacts on L2 writing performance.A positive correlation was found between lexical variation and L2 writing quality,while a significantly negative correlation was shown between lexical errors and writing quality.Meanwhile,concerning the other two dimensions no correlation existed.This reflected that senior high school English teachers paid different attention to various dimensions of vocabulary richness and that there were still other indispensable core criteria in evaluating writing.This study investigated the overall developmental characteristics of lexical richness and the differences of various dimensions between subjects of different language levels,but also analyzed the reasons for the changes and differences,which has important pedagogical implications for vocabulary teaching and learning.Due to the difficulty of collecting students' compositions during the whole three years in this research,future studies are recommended to probe into the development of lexical richness in a longer time span.