In brief
This doctoral thesis pools the results of 113 quantitative studies, published in Turkish and English, that examined how principals’ distributed leadership relates to outcomes for schools and teachers. Across 158 effect sizes, distributed leadership was positively associated with every favourable outcome studied, most strongly with perceived school effectiveness and organisational trust, and negatively associated with organisational stress and intention to leave.
Research problem and aims
Research on distributed leadership has grown quickly, in Turkey as elsewhere, but individual studies use different samples, instruments and outcome variables, which makes the overall picture hard to read. The thesis sets out to estimate the general relationship between principals’ distributed leadership and a wide set of school-level and teacher-level outcomes, and to test whether the size of these relationships differs by school level or by year of publication.
Conceptual framework
The author reviews the main frameworks of distributed leadership, including those of Spillane, Gronn, Elmore, MacBeath, Leithwood, Harris and Timperley, and treats distributed leadership as the sharing of leadership tasks and responsibilities among teachers and other members of the school rather than their concentration in the principal. Sixteen outcome variables are grouped into school-level outcomes, such as organisational commitment, trust, culture, climate, academic optimism and school effectiveness, and teacher-level outcomes, such as self-efficacy, collaboration, professionalism and motivation. Readers new to the concept can start with our page on distributed leadership.
Method
The study is a meta-analysis. The author searched YÖK’s National Thesis Center, ULAKBİM, DergiPark, Web of Science, Scopus, ERIC, ProQuest and Google Scholar, among other sources, for studies completed up to late 2024, with no restriction on country or start date. Studies were included if they examined the relationship between distributed leadership and a school or teacher outcome, reported the statistics needed to compute an effect size, sampled teachers, were theses or peer-reviewed articles, and were written in Turkish or English. From 321 potentially relevant studies, 113 met the criteria, yielding 158 independent effect sizes. Data were coded by the author with the help of two additional coders and analysed in Comprehensive Meta-Analysis software using a random-effects model. Publication bias was examined with the trim-and-fill method, Rosenthal’s fail-safe N and Egger’s regression test; school level was tested as a categorical moderator and publication year through meta-regression.
Key findings
The thesis reports effect sizes as Fisher’s Z. The largest positive values were found for perceived school effectiveness (0.898), organisational trust (0.816), organisational culture (0.757) and organisational climate (0.713). Organisational commitment (0.625), job satisfaction (0.555), organisational citizenship (0.502), academic optimism and teacher professionalism (both 0.490) and academic achievement (0.454) followed. Smaller but still significant positive values were found for teacher collaboration (0.442), self-efficacy (0.419), psychological empowerment (0.399) and motivation (0.396). Distributed leadership was negatively associated with organisational stress and with intention to leave, each at −0.630.
For academic optimism, as an example of the reporting, the pooled value was 0.490 with a 95% confidence interval of 0.403 to 0.577. Neither school level nor year of publication made a statistically significant difference to the size of the relationships.
The author concludes that distributed leadership supports both individual and organisational development in schools and should be seen as a strategic approach for school improvement.
Limitations and implications
The author notes that the analysis is limited to the databases searched, to studies in Turkish and English, to theses and peer-reviewed articles, to samples drawn from education, and to quantitative studies. Readers should also bear in mind that almost all of the pooled studies were correlational and based on teachers’ perceptions of their principals, often measured in the same survey as the outcome. The pooled values therefore describe how strongly perceptions are associated, not the causal effect of distributed leadership, even though the thesis title uses the word “effect”. The author suggests that school leaders treat leadership as a process shaped by all members of the school, not as a function of senior positions alone.
Why it matters internationally
Meta-analytic evidence on distributed leadership is still thin. An earlier review by Tian, Risku and Collin (2016) concluded that the field had been stronger on conceptual debate than on systematic evidence. This thesis brings together a large body of Turkish and international studies, many of them graduate theses that are rarely visible outside Turkey, and its findings are consistent with the view that leadership shared among teachers is associated with a more trusting and collaborative school environment. Because Turkish principals work in a highly centralised system with limited formal autonomy, the strength of these associations in Turkish samples is a useful reminder that distribution is as much about school culture as about formal authority.