The Osmosis Plateau: The Limits of Incidental Vocabulary Acquisition in South African Education Students

Abstract

This study investigates the vocabulary proficiency of undergraduate Bachelor of Education (BEd) students at a South African university. Using a quantitative longitudinal design, students (n = 643) were assessed on high-frequency, mid-frequency, and low-frequency vocabulary levels. Results reveal students perform well below the thresholds required for accessing unsimplified texts. A sharp proficiency decline was observed first at the 3000 word level, and then again at the 5000 word level, with mastery at these levels remaining relatively stagnant across two years of university study. The findings suggest that incidental learning is insufficient for this demographic. Without explicit intervention aimed at building students’ vocabulary knowledge, future teachers risk graduating without the vocabulary knowledge required to mediate the curriculum effectively, perpetuating the country's literacy crisis.