A Causal Model of Transformational School Leadership and Transformational Classroom Leadership on Students' Learning Achievement.

As studies capable of establishing a mediating role of transformational classroom leadership between transformational school leadership and students' learning achievement are short in supply in the Thai high school context, this quantitative study aimed to investigate this role and compared the students' learning achievement among different school sizes. A total of 199 teachers, who taught O-NET and PISA key subjects--45 teachers in English, 77 teachers in science, 77 teachers in math--from the five regions of Thailand representing small, medium, and large school size were recruited through a stratified sampling technique and were asked to rate their principal's transformational school leadership and own transformational classroom leadership. A Thai version of the transformational leadership questionnaire was developed, which consisted of a self-rating and a rater form. Partial Least Square Structural Equation Modeling (PLS-SEM) was employed to find the causal relationship, and ANOVA version SPSS 21 was used to compare the SLA among three different school sizes. The study found that transformational school leadership had direct effects on transformational classroom leadership, but transformational classroom leadership did not have a direct effect on English, science, and math teaching. The study also found that large schools had better students' learning achievement compared to small and medium-sized schools, and small-sized schools had the lowest average score in English, science, and math. Based on these new findings, the study made guidelines for the Thai Ministry of Education, Thai school principals, and Thai teachers. [ABSTRACT FROM AUTHOR]