In the middle of the 1980s, policymakers began to recognize the importance of the teacher as a determinant in students’ learning, based on the findings of researchers such as Brandt (1993), who determined that students’ education is impossible without the instructor. Brandt had the belief that the quality of students is dependent on the quality of instruction, and that the quality of instruction was dependent on the quality of teachers.

Knowles (1980) argued as well that education is a lifelong unending process of continuous inquiry; hence, professional educators need to be lifelong exemplars’ inquirers in order to be able to address the demands of their students. Therefore, continuing education through professional development (PD) is an essential component of teachers’ progress (Fischer et al., 2018; Wei, Darling-Hammond, Andree, Richardson, & Orphanos, 2009). Some academics, such as Avalos (2011), have characterized PD as an ongoing process of teachers’ learning, which includes the process by which they learn and use their knowledge to serve students. This definition can be found in some PD literature. The process of teachers’ learning can be either planned or spontaneous, formal or informal, such as taking part in a variety of courses, reflecting on their own teaching, witnessing the teaching of other teachers, and having talks with other colleagues either before or after they teach (Postholm, 2012).

In 2009, the Organization for Economic Co-operation and Development (OECD) published a report titled Teaching and Learning International Survey (TALIS), which defined professional development as “the body of systematic activities to prepare teachers for their job.” These activities included initial training, induction courses, in-service training, and continuous professional development. PD was also defined as “the body of systematic activities to prepare teachers for their job.”