Sememe richness: a supplementary indicator of lexical richness in Chinese second-language writing

Abstract This article uses the vocabulary measurement indicators of lexical diversity, lexical sophistication, lexical density, and lexical accuracy for second-language writing levels to systematically measure the lexical richness of essays written by Chinese as a second language (CSL) learners. It employs the methodology of building a corpus based on the collected compositions for data analysis. It shows that the Uber index of lexical diversity and the lexical density of CSL learners does not always show a positive correlation with increased test scores. Lexical sophistication usually positively correlates with test scores, but the growth trend tends to be flat from the 81–90 score range. Lexical accuracy below 80 points is positively correlated with writing scores; however, the data above 91 points is slightly lower than that of 81–90 points. This article further hypothesizes that the above measurement indicators fail to accurately measure CSL students’ Chinese lexical ability because those indicators do not include the sememe factors of Chinese words and thus rely too much on word form. This article further puts forward the specific manifestations (polysemes, homographs, and multi-category words) of sememe richness and proposes specific solutions to add sememe richness to the four original formulas through the use of the four above-mentioned measurement indicators in CSL.