Enhancing Lexical Development through Innovative Vocabulary Instruction in a Secondary EFL Classroom A Quasi-Experimental Study

This quasi-experimental study examines the impact of some vocabulary strategies on the lexical development of first-year high school students learning English as a foreign language (EFL) at an educational institution in the Ecuadorian Amazon. Although language learning supports reading comprehension, communication, and general linguistic competence (Nation, 2013; Read, 2000; Schmitt, 2010; Webb & Nation, 2017), it is often taught as a memorization of isolated words. This study involved a three-week instructional intervention that included retrieval practice, spaced repetition, and vocabulary activities designed to promote students' lexical processing. The study employed a quantitative quasi-experimental design with 48 first-year high school students divided into two groups: an intervention group and a control group. Both groups were administered the Updated Vocabulary Levels Test, developed by Webb et al. (2017), with Form A used as a pretest and Form B as a posttest. The results showed that the experimental group scored significantly higher on the posttest than the control group at all vocabulary levels and in the total score. These findings suggest that implementing retrieval, repetition, and contextualized activities can promote the development of receptive vocabulary in secondary school English as a foreign language class, although this study is not considered conclusive causal evidence.