QUASI-EXPERIMENTAL ANALYSIS OF THE EFFECTIVENESS OF INTEGRATING THE "CHEMIST 5.0.3" MOBILE APPLICATION INTO CHEMISTRY LESSONS.

This study conducts a quasi-experimental analysis of the effectiveness of integrating the CHEMIST 5.0.3 mobile application into secondary-school chemistry lessons.

Two intact, parallel classes (Grades 8–9; one experimental, one control) completed a 4–6 lesson mini-module on solutions, pH, and buffers. The experimental group used CHEMIST 5.0.3 for interactive visualization, guided problem solving, and micro-lab planning, while the control group received methodologically equivalent instruction without the app. Outcomes included a validated concept test (pre/post and a 2-week retention test), rubric-scored practical tasks (procedure adherence, interpretation quality), a brief cognitive-load scale, and a time-on-task–normalized efficiency index. Data analysis followed an ANCOVA framework with pre-test as covariate and reported effect sizes (Cohen’s d/Hedges’ g); inter-rater agreement for rubric scores was estimated via Cohen’s κ, and internal consistency via KR-20/α. Content validity was ensured through expert review. The study documents whether mobile integration improves conceptual understanding, transfer to practice, and learning efficiency while maintaining acceptable cognitive load, and discusses methodological limitations and classroom implications for scalable, resource-aware adoption.