Receptive vocabulary size is considered to be closely related to EFL writing quality, but it is less known whether productive vocabulary size contributes to writing quality. It is speculated that large vocabulary size leads to long composition; however, there's no data to verify the hypothesis. To date few studies have related vocabulary size to lexical richness at the same proficiency level. Laufer and Nation (1995) have proposed a new measure of lexical richness-the Lexical Frequency Profile (LFP). It categorizes the vocabulary used in the discourse into frequent, less frequent and infrequen...
