This study explores the comparative impact of Technology-Enhanced Van Hiele Phased Instruction (TVHPI) and Conventional Van Hiele Phased Instruction (VHPI) on secondary school learners’ attitudes, experiences, and understanding of transformation geometry. Utilizing quantitative and qualitative methods, the study analyzed data from 483 learners through a Difference-in-Differences (DiD) approach and conducted in-depth interviews with 48 students from six secondary schools in mid-western Uganda. Quantitative findings revealed a significant improvement in attitudes towards geometry in the TVHPI group, as evidenced by higher post-test attitude scores (M = 3.62, SD = 0.496) compared to the VHPI group (M = 3.49, SD = 0.506). The TVHPI method, integrating GeoGebra, demonstrated a greater positive attitudinal shift (Z = -13.008, p < .01) than the VHPI method (Z = -12.474, p <0.05). Sensitivity analysis confirmed the robustness of these results, suggesting the potential of technology-enhanced instruction in improving learners’ attitudes toward transformation geometry. The qualitative analysis further examined learners’ conceptual understanding and experiences. Findings highlighted that while both instructional strategies improved students' knowledge of transformation geometry, TVHPI, emphasizing visualization and engagement through GeoGebra, was more effective in overcoming conceptual difficulties and fostering deeper comprehension. Learners in the VHPI group struggled more with geometric concepts and required additional instructional support. The study highlights the importance of integrating technology like GeoGebra into the Van Hiele instructional model to enhance both learner engagement and understanding of geometry. It recommends the adoption of TVHPI in secondary education to support positive attitudinal shifts and better conceptual outcomes. Furthermore, the proposed Geometry Pedagogical Improvement Cycle (GeoPIC) offers a structured framework for continuously improving geometry teaching, balancing traditional and technology-enhanced methods to cater to diverse learner needs.