The authors cast a deliberately wide net. They searched four major databases: Web of Science, Scopus, the TR Index, and the Higher Education Council National Thesis Center, which catalogs graduate theses from Turkish universities. That last source matters enormously, because in Türkiye a large share of curriculum research has been produced by master’s and doctoral students rather than by established academics publishing in indexed journals. The team then applied thematic content analysis, a technique that codes each study according to categories such as research method, participant group, data collection instrument, and topic, allowing patterns across hundreds of individual investigations to emerge from the aggregate.

The clearest signal in the data is temporal. Interest in mathematics curriculum research did not accumulate steadily; it surged after major policy interventions. Türkiye revised its mathematics curriculum repeatedly during the review period, with official documents issued in 2005, 2009, 2013, 2018, and most recently 2024 under the so-called Türkiye Century Maarif Model. Each revision triggered a fresh burst of studies examining what had changed, how teachers interpreted the new documents, and whether the intended innovations were reaching classrooms. The review’s authors describe this reform-driven rhythm as the dominant force shaping the field’s trajectory, with publication peaks tracking closely behind official curriculum updates.

Methodologically, the picture is lopsided. Most of the studies reviewed employed qualitative designs, with case studies and document analyses dominating the landscape. Document analyses, in particular, became a signature approach: researchers compared successive curriculum documents against one another, evaluated them through established frameworks such as Tyler’s objectives-based model, Stufflebeam’s CIPP model, or Eisner’s educational criticism model, and examined how constructs like mathematical literacy, estimation skills, geometric habits of mind, and twenty-first-century skills were represented across different eras. Quantitative and mixed-methods work, by contrast, occupied a much smaller share of the literature, and experimental designs were rare.

The instruments researchers used tell a similar story. Surveys, interviews, observations, and achievement tests were the workhorses of data collection, reflecting the field’s preoccupation with capturing perceptions rather than measuring outcomes. That preoccupation extends to who was studied. The overwhelming majority of investigations focused on mathematics teachers and classroom teachers, soliciting their views on the curriculum, their concerns during implementation, and their proficiency with the assessment methods the reforms demanded. Studies probing how students experienced the curriculum, or how it affected learning over time, were comparatively scarce.

Thematically, three clusters stand out. The first concerns teachers’ perceptions of the curriculum: how they understood the constructivist philosophy underlying the 2005 reform, what worries they expressed during its first year, and how they judged its feasibility in real classrooms. The second is curriculum evaluation, a genre in which researchers systematically appraised official documents against theoretical criteria. The third is comparison, both national and international. Turkish scholars have compared their curricula with those of Estonia, Canada, and Singapore, and have traced the historical evolution of their own programs back through the republican period and even to 1948, examining how general aims, content organization, and pedagogical principles shifted across generations of reform.

That historical thread is one of the field’s genuine strengths. Studies have analyzed curricula dating from 1924 onward, charting the rise of the spiral approach, in which topics are revisited at increasing levels of sophistication, and documenting the long arc from behaviorist aims toward competency-based goals. Such work situates Türkiye’s recent reforms within a century-long story of educational modernization and connects national debates to international frameworks like the National Council of Teachers of Mathematics standards, which influenced the 2005 redesign. For international readers, the review offers a case study in how a single national system has repeatedly translated global curriculum theory into local policy.

Yet the review’s most consequential finding is what is missing. Despite the volume of research, the authors conclude that the field has expanded in breadth while remaining limited in depth, particularly regarding comprehensive evaluation of how curricula are actually implemented and whether they work. School administrators and parents, the stakeholders who shape and experience curriculum reform from outside the classroom, are almost entirely absent from the literature. And because so few studies used experimental, longitudinal, or action research designs, the field can say a great deal about what documents intend and what teachers think, but very little about causal effects on student learning or about how implementation unfolds over multiple years.

The authors’ prescription follows directly from the diagnosis. They call for experimental and longitudinal studies capable of testing whether curricular changes improve outcomes, for action research that embeds evaluation within teachers’ own practice, and for mixed-methods approaches that combine the interpretive richness of qualitative work with the inferential power of quantitative measurement. They also argue that the accumulated evidence now needs synthesis at a higher level: meta-analyses that pool effect estimates across studies, and bibliometric analyses that map the intellectual structure of the field, would convert two decades of scattered findings into a coherent knowledge base capable of informing the next round of reform.

The stakes extend well beyond Türkiye. Curriculum reform is a global industry, and the Turkish experience mirrors patterns documented elsewhere: reforms announced with ambitious constructivist rhetoric, followed by studies of teacher buy-in, followed by persistent uncertainty about impact. The review suggests a cautionary lesson for education systems everywhere. A research literature can be voluminous and still leave the central question, does this curriculum help students learn mathematics, unanswered. Closing that gap requires not more perception studies but a deliberate shift toward designs that can track implementation and measure effectiveness over time. As Türkiye prepares to implement its 2024 Maarif Model curriculum, the review offers both a map of what has been learned and a warning about what remains unknown.

Subject of Research: Systematic review of mathematics curriculum research trends in Türkiye over two decades

Article Title: A systematic review of mathematics curriculum studies in Türkiye: trends and insights over two decades

Article References: Birgin, O., & Türkmen, H. İ. (2026). A systematic review of mathematics curriculum studies in Türkiye: trends and insights over two decades. SN Social Sciences, 6(10), Article 486. https://doi.org/10.1007/s43545-026-01783-0

Image Credits: AI Generated

DOI: 10.1007/s43545-026-01783-0

Keywords: mathematics curriculum, Türkiye, systematic review, curriculum evaluation, education reform, constructivism, qualitative research, teacher perceptions, research methods, mathematics education, curriculum comparison, longitudinal studies