Abstract
Persistent gaps in mathematics achievement, particularly for students with disabilities (SWD) and mathematics difficulties (MD), highlight the need for instructional approaches that explicitly address the linguistic demands of mathematics. Mathematics vocabulary (MV) is foundational to interpreting problems, understanding procedures, and communicating reasoning, yet it is often taught implicitly. This dissertation examined the effects of Content Acquisition Podcasts for Students (CAP-S), a structured, multimedia-based vocabulary intervention grounded in cognitive load theory and the cognitive theory of multimedia learning, on sixth-grade MV outcomes.
Using a counterbalanced quasi-experimental design, 190 students in a rural middle school, including 55 identified as SWD or MD, participated in CAP-S and business-as-usual (BAU) conditions across two marking periods. CAP-S videos (1-2 minutes each) provided explicit, visually and verbally integrated instruction on targeted vocabulary terms. Mixed-effects analyses controlling for prior mathematics achievement revealed large pretest-to-posttest gains across all students (dz = 1.32), with learning largely maintained over time (dz = 0.99). SWD or MD demonstrated significant growth (dz = 0.93) and a moderate marking-period advantage under CAP-S compared to BAU (d = 0.50). For students without disabilities or MD, CAP-S effects were particularly strong during the second marking period (d = 1.65), suggesting increasing value as content complexity intensified.
The findings from this dissertation ultimately promote that explicit, theory-aligned multimedia vocabulary instruction can produce durable gains and function as both a targeted and universal support in general education mathematics classrooms. CAP-Ss offer a feasible, scalable approach to strengthening access to rigorous middle school mathematics content.
