Previous studies have shown that explicit vocabulary learning leads to vocabulary acquisition; however, the link between implicit vocabulary learning and vocabulary acquisition seems to be under-researched. It was unclear whether vocabulary development was positively or adversely affected by attending English classes and preparing for examinations. In order to address this issue, this research investigates the vocabulary size of 78 first-year university students in 2018. The vocabulary size was measured at the beginning and at the end of the school year using the Vocabulary Size Test (Nation & Beglar, 2007). It was found that students gained about 300 words on average through the year. The result shows that even though the students received limited explicit instruction on the vocabulary tested, they generally improved their English vocabulary over time. Their attendance rate and their scores in the review tests, however, were found to have no significant associations with the vocabulary gain.
Fukuda et al. (Tue,) studied this question.