Development of a CODE-Based Teaching Guide on the Central Dogma in Biochemistry: A Study in the Philippines

Abstract

This study developed and validated the CODE Instructional Approach (Case-Organized, Dramatized, and Embodied) to enhance preservice science teachers’ understanding of the Central Dogma of Molecular Biology. A total of twelve (12) third-year BSED Science students enrolled in PHSc108 Biochemistry participated in the implementation phase of the study. Using the ADDIE instructional design model, the Analysis Phase revealed several learning needs, such as students' persistent misunderstandings, difficulty visualizing molecular processes, and a strong preference for visual and hands-on learning strategies. A panel of seven qualified evaluators assessed the instructional materials for validity, clarity, and pedagogical integrity. The overall validity rating for the pretest–posttest instrument was 3.77, and the rating for the Teaching Guide was 3.70, both interpreted as “very highly valid.” The mean score for students' conceptual understanding increased from 14.25 to 20.17, representing a substantial improvement. The Wilcoxon Signed-Rank Test confirmed that this increase was statistically significant (Z = –3.068, p = .002), with a very large effect size (r = 0.886). Thematic analysis of student reflections identified four themes: misconceptions regarding the direction of genetic information flow, difficulty understanding molecular processes, incomplete understanding of mutation, and a preference for visual and experiential learning. Overall, the results show that the CODE Approach effectively addresses gaps in understanding by integrating multimodal, contextualized, and embodied learning activities.