The "purpose" of this mixed methods study was to understand and describe self-reported experiences with effective School Improvement strategies used by school heads in primary and secondary schools. Focus group interviews and surveys with parents, school heads and teachers helped to inform the research questions identified for this study. The overall "findings" reveal that schools' organizational efficacy is collectively achieved when school headmasters practice and implement instructional leadership strategies and behaviors gleaned through the following five broad professional growth-oriented themes emerging from this study: (a) using inclusive leadership strategies; (b) encouraging team-work among teachers; (c) teacher participating in collective information gathering to create a shared school vision; (d) and leadership helping to fulfill contractual agreements among teachers, students and parents; and (e) ensuring availability of instructional resources and technology. From the findings of the current study, we reached the general "conclusion" that information availability and processing at school level will always allow for increased collective participation by teachers in the school improvement (SI) agenda through the enhancement of holistic organizational learning power. Schools that learn as organizations improve fast.