Informal Professional Development for Enhancing a High School Mathematics Teacher’s Blended Learning Data Practices

The purpose of this mixed methods action research study was to examine how I, an in-serve high school mathematics teacher, used informal professional development to build capacity for implementing blended learning data practices. The study investigated how designing and implementing digital formative assessments informed instructional adjustments, strengthened differentiated instruction, and influenced student academic performance and self-efficacy. The intervention was conducted during the 2024-2025 school year in an Algebra 2 Honors classroom with 29 students. Data sources included digital warm-ups and exit tickets, pre- and post-intervention self-efficacy surveys, practitioner-researcher journal, and critical friend field notes. Three action research cycles of investigation, analysis, and action were completed to analyze and refine instructional practices. Findings indicated that data-driven decision-making strengthened instructional responsiveness and that data-informed mastery-level grouping enhanced differentiated learning. Pedagogical alignment, scaffolding, and student-centered design contributed to improved academic performance, while technology facilitated access and presented barriers to full integration. Students reported that peer modeling, mastery-oriented practice, and a supportive classroom environment enhanced their confidence and engagement. Overall, the iterative cycles of action research functioned as an effective form of informal professional development, fostering growth in my blended learning competencies. The study contributes to a classroom-based model demonstrating how teachers can use data practices to enhance academic performance and self-efficacy in the absence of formal professional development.