The impact of vocabulary instruction on science learning in a secondary science course

Abstract

This investigation focused on the most effective instructional strategies for helping students learn science vocabulary in a ninth grade biology classroom (N=30). Students were divided into two groups, and received instruction using either established methods, control group (n=15), or innovative methods, intervention group (n=15). The investigation continued during two units of instruction (approximately three weeks each), with students receiving different instructional treatment for each unit. Innovative methods were informed by several vocabulary learning theories, most specifically Social Constructivism/Sociocultural Theories, Schema and Psycholinguistic Theories, Dual Coding Theory, and Motivation Theory. Student growth was measured using pretests and posttest of vocabulary terms, and analyzed using normalized gain. Vocabulary performance showed larger normalized gains for the intervention group. Mean normalized gain for the intervention group was 0.653, while mean normalized gain for the control group was 0.483. Other measures of student learning were also collected, with surveys giving insight into student preferences. A Likert scale survey measuring preference and confidence showed slightly more positive responses for the intervention group An open-ended survey analyzed using word clouds also indicated slightly more positive responses by students in the intervention group. Finally, student scores on vocabulary posttests and summative unit tests showed a positive correlation between vocabulary acquisition and broader classroom success. Linear regression of student unit test scores (mean for both units) versus posttest scores (mean for both units) showed that 45% of test score differences were explained by differences in vocabulary posttests. This investigation showed that intervention methods were more effective at helping students learn science vocabulary, were slightly preferred by students, and had a strong correlation with broader measures of student performance in this biology classroom.