Inclusion criteria | Exclusion criteria |
· Empirical studies within the field of educational leadership · Peer-reviewed journals · Articles published in English · Articles published between 2016 and 2019 · Articles including primary and secondary school systems · Articles showing a relationship between educational leadership and at least one of the following keywords: school improvement, staff development and leadership styles. | · Articles written in other languages · Articles which were not specified as empirical studies · Articles which were not peer-reviewed · Articles that were published prior to 2016 |