Purpose: Drawing from the equitable education fund (EEF) launching 6Qs innovation in the teacher school quality program (TSQP) for small and medium schools, this research aims to analyze the effect size of the ordinary national educational test (O-NET) scores between TSQP schools that implement 6Qs innovation and non-TSQP schools and explain the impact of 6Qs innovation on O-NET scores' effect size. Design/methodology/approach: This study adopts an explanatory sequential mixed-method design. The quantitative study investigates the impact of the 6Qs innovation by analyzing the effect sizes of O-NET scores in four subjects of sixth-grade students. The effect size is analyzed by comparing the mean between 221 TSQP schools and non-TSQP schools: 16,197 small and medium schools throughout Thailand. The qualitative study uses a field study with administrators and teachers through in-depth interviews and focus groups in 13 good practice schools. Findings: The quantitative result shows that 22 to 35% of TSQP schools demonstrated effect size within the standard level, meaning that their O-NET scores are higher than those of non-TSQP schools. Findings from 13 good practice schools indicate that both administrators and teachers have embraced and implemented the 6Qs innovation to establish an organizational culture that emphasizes 6Qs as a coordinating framework, which significantly influences students' learning outcomes. Originality/value: Although this research is studied in the Thai context, the 6Qs innovation with implementations extracted from the good practice schools can be generalized to any school in a similar context. A section on such innovation is provided in practical implications.