A Study On Development Of Lexical Richness In Senior High School Students’ English Writing

Lexical richness is regarded as an indicator of English learners’ writing ability and overall linguistic competence.In recent years,it has been concerned by numerous scholars in the field of second language acquisition.The previous studies mostly focused on university students or graduate students.While the studies of senior high school students were deficient and the dimensions of lexical richness in previous studies were not comprehensive enough.The focus of this thesis is centered on development of lexical richness for three grades’ senior high school students by the cross-sectional method in the research.The lexical richness would be demonstrated from four dimensions including lexical variation,lexical sophistication,lexical density and lexical error.The research questions of thesis include:(1)What are the developmental features and trends of lexical richness for senior high school students across three grades?(2)What are the correlations between lexical richness and writing quality for senior high school students across three grades?120 compositions with the same subject written by students of three natural classes in three grades of a senior high school were collected,and then three small corpora were built based on different grades.The number of samples in each corpus is 40.The study researches lexical richness by using quantitative approach.The software Tree Tagger,Antconc and Range32 are used in marking and processing writing materials,and descriptive analyses including One-way ANOVA test,Post hoc test and Pearson correlation analysis are achieved by means of software SPSS 23.0.The research results are listed below:(1)In terms of developmental features and trends of lexical richness,each dimension of lexical richness has different degrees of development in three grades,and the improvements are unbalanced with diversified trends.Lexical variation develops non-linearly with a rapidly growing up from Grade 1 to Grade 2 and a slowly going down from Grade 2 to Grade 3.It rises to the highest point in Grade 2,and then faces degeneration in Grade 3.The notable difference is only demonstrated by students in Grade 1 and Grade 2.The significant difference is not found in other comparative groups.Lexical sophistication increases non-linearly among three grades.From Grade 1 to Grade 2,it grows up sharply but the increase from Grade 2 to Grade 3 is extremely slight.Lexical sophistication in Grade 3 is stagnant and it faces the plateau phenomenon.There is no significant difference of lexical sophistication from Grade 1 to Grade 3.Lexical density goes up non-linearly in three grades.There exists a gradual increase from Grade 1 to Grade 2,and a sharp increase occurs from Grade 2 to Grade 3.Significant differences are found in each adjacent group.Lexical error basically reveals a linear pattern of dropping off,and it reaches the lowest point in Grade 3.There exists a significant difference in Grade 1 and Grade 3.The significant difference of lexical error is not found among other grades.(2)In terms of the correlations between lexical richness and writing quality,there are different correlations between each dimension of lexical richness and writing quality,and the correlations are different in each grade.Lexical variation is significantly correlated with writing quality in all three grades,but the positive correlation in Grade 2 is not as strong as that in Grade 1 and Grade 3.The significant positive correlation of lexical sophistication and writing quality is only found in Grade 2.There is no significant correlation between lexical density and writing quality.Highly significant negative correlations between lexical error and writing quality exist in Grade 1 and Grade 3.