Classroom Behavioral Protocol to Assess Contextual Diversity and Lexical Alignment in Second-Language Vocabulary Learning

This methods article presents a classroom-based behavioral protocol for preparing reading input with controlled contextual diversity, eliciting lexical reuse in continuation writing and peer discussion, and assessing second-language vocabulary over time. The protocol distinguishes contextual-diversity conditions from observed lexical-alignment behavior and specifies analyses that account for pair membership. Ninety-six students were recruited, 94 consented and were screened, and 86 learners participated in 43 pairs. Their mean age was 20.4 years, with 50 female and 36 male participants. The target set comprised 24 words, with 12 assigned to each contextual-diversity condition. Mean total vocabulary scores, averaged across the two task categories, were 11.40 at pretest, 24.25 at the immediate posttest, and 21.65 at the 7-day delayed posttest. These descriptive summaries show an increase after the classroom session and a partial decline in delayed testing. Fixed word-to-condition assignments and repeated use of identical tests limit causal interpretation. The protocol specifies procedures for preparing materials, administering tasks, coding lexical reuse, assessing reliability, and analyzing repeated item-level outcomes.