Problem-Based Learning with Scaffolding Assisted by Mobile Technology: Enhancing Students' Understanding of Chemical Kinetics

Abstract

Chemical kinetics is a vital yet conceptually abstract, mathematically demanding, and often challenging topic for secondary school students, necessitating innovative instructional approaches to improve conceptual understanding, foster real-world relevance, and strengthen problem-solving skills. This study examined the impact of integrating Problem-Based Learning (PBL) supported by mobile technology and structured scaffolding on students’ conceptual learning of chemical kinetics in non-governmental secondary schools in Addis Ababa, Ethiopia. A mixed-methods intervention research design was employed, involving three instructional groups: (1) PBL with mobile technology and scaffolding, (2) PBL with scaffolding alone, and (3) conventional lecture-based instruction. The instructional content addressed core topics including reaction rates, factors affecting rates, rate laws, and graphical interpretation of rate data. Quantitative data were collected through pre- and post-tests, with analyses providing evidence supporting the validity of the data for this specific population, and analyzed using Analysis of Covariance (ANCOVA). Qualitative data were gathered through semi-structured interviews and classroom observations to capture students’ engagement levels, collaborative learning experiences, and perceptions of the instructional strategies. Post-test findings showed a statistically significant instructional effect (p < .001), with the PBL with mobile technology and scaffolding group achieving the highest mean score (M = 44.24), followed by the PBL with scaffolding group (M = 37.03), and the lecture-based group (M = 31.00). Qualitative findings highlighted enhanced student engagement, collaboration, and problem-solving confidence, with mobile simulations helping make abstract reactions more concrete. A post-hoc analysis further confirmed the robustness of the intervention effect across subgroups. The study concludes that integrating PBL with mobile technology and scaffolding offers an effective instructional model for improving conceptual understanding in chemical kinetics and recommends expanding access to mobile learning tools and incorporating technology-enhanced PBL in science curricula.