<![CDATA[This study developed and preliminarily evaluated a problem-based learning (PBL)-oriented chemistry e-module on the Law of Conservation of Mass for Phase E students. A modified seven-stage Borg and Gall research-and-development procedure was used, comprising problem analysis, data collection, product design, expert validation, design revision, staged product trials, and final revision. Qualitative evidence was obtained from observations, interviews, needs analysis, and expert comments, while quantitative evidence comprised expert-validation percentages and pretest-posttest learning-motivation questionnaire scores. The e-module was reviewed in two rounds by a chemistry-content expert and an instructional-design/media expert. Its overall mean feasibility scores were 81.43% for content and 91.70% for design and media. Formative trials involved three students in a one-to-one trial and six students in a small-group trial. Mean motivation scores increased from 70.67% to 92.33% (mean normalized gain = 0.72) in the one-to-one trial and from 69.33% to 90.83% (mean normalized gain = 0.7033) in the small-group trial. In the field trial, motivation scores increased from 76.90% to 93.22% in Class X.7 and from 76.03% to 93.60% in Class X.8, with reported mean normalized gains of 0.7070 and 0.7116, respectively. These findings indicate that the e-module was feasible and was associated with substantial within-group improvement in self-reported motivation. Because the field evaluation used no control group or random assignment, the results should be interpreted as preliminary evidence rather than a causal estimate of effectiveness.]]>
