“…School administrators play a significant role in creating a school vision, establishing professional community partnerships, maintaining and delivering effective communication, supporting and promoting teacher professional development, building teamwork, delegating tasks and administration, promoting curriculum development, and enhancing staff morale. English as the medium of instruction used by foreign teachers enables students to think and use English in a meaningful way because they not only need to employ the four language skills (listening, speaking, reading, and writing), but they also develop other relevant skills such as critical thinking, ICT, intercultural communication, and interpersonal relationship (Borg et al, 2014;Forman, 2016). Recruiting qualified foreign teachers, producing competent Thai English teachers, and reconsidering foreign teacher salaries are the demands of highly effective schools for the Ministry to consider in order to facilitate the teaching and learning process and thereby promote students' English achievement (OECD/UNESCO, 2016; UNESCO, 2014).…”