The aim of this research was to explore undergraduates’ receptive and productive knowledge of vocabulary and how these relate to academic achievement in order to improve educational outcomes for students. The research was divided into two phases. In the first phase, an estimate of UG students’ receptive vocabulary knowledge was measured by administering a vocabulary size test devised by Goulden et al (1990) to 389 undergraduates in one HE institution. In Phase II, an estimate of UG students’ productive vocabulary knowledge was measured by examining the lexical richness of 41 UG students’ written work, totalling 369 assignments, using AntWordProfiler software. Both phases tested for correlations between vocabulary knowledge and academic achievement measured using degree classifications in Phase I and marks on assignments in Phase II.
Key findings from Phase I suggest undergraduates have an estimated vocabulary size of around 11,000 words. The study also found that students’ vocabulary sizes change between Stages 1 and 2. It was hypothesised that vocabulary sizes would play a role in academic achievement as measured by degree classifications. However, no correlation between vocabulary sizes and academic achievement was found and there is no difference between the mean vocabulary size of students predicted a first [(x ̅) = 11,521] and those who were predicted an upper second-class [(x ̅) = 11,312]; lower second-class [(x ̅) = 11,450] and a third class [(x ̅) = 9,833] degree.
Key findings from Phase II indicate that most of the words that students use in their writing are low frequency or K1 Words (the first 1,000 most frequent words in English). However, the proportion of K1 words used decreases from Stage 1 to 3 and student writers are using more academic words from the New Academic Word List (NAWL) in Stage 2 as compared to Stages 1 and 3. It was also found that as students progress through their degree, they use more words from the New General Service List (NGSL) 2 and 3 in addition to the NAWL in Stage 2. Furthermore, students used more ‘off-list’ words in Stage 3 compared to Stages 1 and 2. This suggests that students do experience change in their academic vocabulary while at university.
No correlations between marks on students’ assignments and the percentage of academic words used from the NAWL were found. However, correlations were found with the general English word lists. A medium, negative correlation was found between marks on assignments and K1 words in Stage 1 and a small correlation in Stage 2. There is also a small positive correlation between the usage of K2 words used in student assignments and marks in Stage 1 but not in Stage 3. In terms of the NGSL 3, no correlations were found in Stages 1 and 3 in relation to marks but there is a small positive correlation in Stage 2.
This indicates that students achieving higher marks use fewer high frequency and more low frequency words in their assignments. Although these correlations are not strong enough predictors, they still could have some consequence for student achievement; it implies that students need to write with a degree of lexical richness to achieve higher marks.
By capturing UG students’ vocabulary knowledge, this research contributes to our current understanding of students’ vocabulary size, types of vocabulary needed for degree success and methods of measuring vocabulary to better inform practitioners in HE as well as those interested in vocabulary research.