Development and Validation of Strategic Intervention Materials (SIMs) of the Selected Topics in Trigonometry of Precalculus Discipline in Senior High School

Shaped with Vygotsky’s Principle on Scaffolding, this study aimed to develop and validate learning materials known as Strategic Intervention Materials (SIMs) of the selected topics in Trigonometry in the STEM strand. This developmental study undertook three phases, namely: planning, development, and validation and guided by the ADDIE Model in the data analysis. In the planning stage, the least-mastered competencies (LMC) were selected based on the results of their final examination in Pre-Calculus in the field of Trigonometry. The researcher made two SIMs based on the identified (LMC). The second stage is the development of the materials that were presented and critiqued by the thesis adviser, students, colleagues, and SIM experts. In the last stage, the content and student validators validated the developed learning materials. The validators were purposively chosen. The adapted instrument was used in validating the materials. The developed SIMs were rated “excellent” by the content-validators and “more than adequate” by the student-validators. This implied that the content-validators considered the SIMs as teacher support materials that can be used to master the competencies in Pre-Calculus and learner enhancers to improve their competence as evaluated by the student-validators. The validation results of the two SIMs paved the way for the construction of the new learning material to confirm the findings and undergone validation were rated “excellent” and “more than adequate” by content and student validators respectively. It is recommended that teachers should develop more SIMs for other disciplines to address students’ difficulties in learning Trigonometry.