Lexical Richness of Chinese College Students’ Spoken English
Lexical richness has been considered one of the most effective methods of assessing writing proficiency. However, the studies on spoken English lexical richness for EFL Chinese students are relatively few. By comparing low, middle, and high levels of Chinese college students’ spoken English, based on Read’s (2000) and Costa’s (2005) framework, this study investigates the developmental features of lexical richness in terms of three dimensions: lexical sophistication, lexical variability, and lexical density. With the help of LCA, SpaCy, and Antwordprofiler, this quantitative study evaluates more than 150000 tokens and analyzes the data using SPSS. The findings are as follows: 1) Chinese college students’ spoken English lexical variability increases significantly with the increase of the English levels; 2) Chinese college students’ spoken English lexical sophistication increases with the increase in the English levels, but it has a critical point of growth rate, using the unique method--“avoidance”; 3) Chinese college students’ spoken English lexical density firstly decreases and then increases with the increase of the English level, and the low-level learners use the fewer conjunctions which probably causes the higher lexical density. 4) Costa’s (2005) psycholinguistic model can explain the language features in a non-specific language view. Based on the above conclusions, some suggestions are put forward for oral English teaching to improve the students’ oral English ability.