Page 42 - Educational Leadership in a Changing World

Rasa Nedzinskait˙ e-Mači¯ unien˙ e and Antonios Kafa

at their school (Organisation for Economic Co-Operation and Develop-
ment, 2024). Higher scale score values indicate that the school leader,
teachers or members of the school management team, and the school
governing board had a greater level of autonomy in decision-making
activities at their school. Lower scale score values indicate that these
groups had less autonomy.

Dependent Variable
As a dependent variable in this study, students science scores in the lat-
est oecd pisa results were selected. Scientific performance, for pisa,
measures the scientific literacy of a 15-year-old in the use of scientific
knowledge to identify questions, acquire new knowledge, explain scien-
tific phenomena, and draw evidence-based conclusions about science-
related issues (Organisation for Economic Co-Operation and Develop-
ment, 2023a). In the 2022 Programme for International Student Assess-
ment (pisa), the average science score among oecd countries was 485
points (Organisation for Economic Co-Operation and Development,
2023b).

Mediator/Moderator
Economic, social, and cultural status (escs) was chosen as media-
tor and moderator between school autonomy, principal instructional
leadership and science achievement. escs is the oecd pisa 2022 in-
dex of economic, social and cultural status. escs is a composite score
derived, as in previous assessments, from three indicators related to
family background: parents’ highest education, in years (paredint),
parents’ highest occupational status (hisei) and home possessions
(homepos) (Organisation for Economic Co-Operation and Develop-
ment, 2023a). It must be mentioned that this index is constructed from
students’ survey results. The higher the value of escs, the higher the
socioeconomic status. The escs scale has a mean of 0 and a standard
deviation of 1 across oecd countries (Organisation for Economic Co-
Operation and Development, 2023b).

Data Analyses
To examine the relationships between instructional leadership, school
autonomy, Economic, Social, and Cultural Status (escs), and students’
science achievement, the analysis of mediation and moderation was

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