Exploring the Relationship between Vocabulary Size and Reading Comprehension: A Study Based on VLT and PET Scores among Mongolian University Students

Abstract

This study investigates the relationship between vocabulary size and reading comprehension among 75 Mongolian university students using Paul Nation’s Vocabulary Levels Test (VLT) and the PET reading test. The aim was to determine whether students' receptive vocabulary knowledge predicts their ability to comprehend written English. Descriptive statistics, Pearson correlation, group comparison, and linear regression analyses were performed. Results showed a statistically significant but modest positive correlation (r = 0.24, p = 0.038) between vocabulary size and reading scores. Learners with more than 5000 word families tended to perform better, though the difference was not statistically significant. Regression analysis revealed that vocabulary size accounted for 5.7% of the variance in reading comprehension scores. These findings suggest that vocabulary knowledge contributes meaningfully to reading ability, although it alone does not fully explain performance. The study highlights the need for structured vocabulary instruction in EFL contexts and calls for further research into additional factors affecting reading development among Mongolian learners.