Data literacy has emerged as a fundamental competence for navigating societies increasingly shaped by data‑intensive technologies, digital infrastructures, and algorithmic decision processes. Within education systems, the capacity to collect, interpret, analyse, and ethically use data is essential for civic participation and for enabling students and educators to make evidence‑based judgments and decisions. Although related to statistical, digital, information, and AI literacies, scholarship contends that data literacy is distinctive because it integrates technical, cognitive, ethical, and communicative dimensions oriented toward purposeful uses of data in authentic contexts (Wolff et al., 2016; Knaflic, 2020). In schools, this conception goes beyond reading graphs and tables to encompass the formulation of meaningful questions, the production and curation of data, the critical appraisal of evidence, analytical decision‑making, and the ethical communication of findings. It also demands vigilance regarding risks of misuse—including surveillance, bias, stigmatisation, and inequality reproduction—highlighted in critical accounts of educational datafication (Mandinach & Gummer, 2016; Prinsloo & Slade, 2017; Williamson, 2017).

In Portugal, curricular reforms over the past decade have emphasised transversal competencies, interdisciplinarity, and project‑based pedagogies. Nevertheless, data‑related competencies remain unevenly distributed across subjects and cycles and often appear implicitly or as subordinate elements within Mathematics and Science. While the label ‘data literacy’ is rarely explicit in national curriculum documents, aligned practices and learning goals are visible at multiple levels—from early exploratory activities to formal statistical study in upper secondary—and are consolidating through pedagogical innovation initiatives, including the pilot subject ‘Literacies and Data.’ This landscape justifies a focused inquiry into how data literacy is conceptualised and embedded in the curriculum as written, and how it is understood and enacted by educational actors in everyday practice.

To guide this inquiry, the study poses two research questions that reflect its dual emphasis on curricular framing and practitioner perspectives: first, how and where data‑literacy‑related competencies are embedded—explicitly and implicitly—within Portugal’s compulsory education curriculum; and second, how teachers, school leaders, and other educational actors understand data literacy and perceive their readiness, practices, and challenges related to its implementation. Together, these questions connect system expectations with lived practices in schools, providing a lens to identify convergences, gaps, and opportunities for more systematic integration.

Conceptually, the study adopts a theoretical framework that synthesises three strands. The first is a multidimensional view of data literacy integrating domains as technical (collection, analysis, visualisation), cognitive‑critical (interpretation, argumentation), communicative (including data storytelling), ethical‑civic (privacy, fairness, accountability), oriented to authentic tasks and contexts (Wolff et al., 2016; Knaflic, 2020). The second draws on research into data‑informed educational decision‑making, which shows that educators’ engagement with data depends on professional knowledge, collaborative cultures, leadership, time, and tools; it distinguishes mere access to data from meaningful, practice‑proximal use that supports assessment, pedagogical differentiation, and school improvement (Datnow & Park, 2018; Mandinach & Gummer, 2016). The third incorporates insights from critical data studies, foregrounding ethical and justice‑oriented dimensions, supporting the systematic inclusion of privacy, transparency, and accountability (Prinsloo & Slade, 2017; Williamson, 2017).

By integrating these strands, the study conceptualises data literacy as a cross‑curricular, pedagogical, and ethical priority whose coherent progression depends on clear curricular expectations, practice‑proximal professional learning, and supportive organisational conditions. Situated within DATA‑READY (Empowering Education through Data Literacy Integration in Compulsory Education), ERASMUS-EDU-2024-POL-EXP-DIGITAL, No. 101195801, an European project that aims to develop a European Framework for Data Literacy to guide curriculum planning, teacher education, and inclusive educational policies, the present investigation examines the Portuguese case.

The study adopted a convergent mixed methods design, combining a documentary analysis of key curriculum and policy documents with an online survey of educational actors. The two strands were conducted in parallel and integrated through triangulation and joint displays, which enabled a systematic alignment between prescribed curriculum expectations and the perceptions, practices, and needs reported by practitioners. This design provided a macro level perspective anchored in official texts and a meso/micro level perspective grounded in the lived experiences of teachers, school leaders, and specialist staff across educational levels and disciplinary areas. The documentary analysis drew on a corpus that included the Profile of Students at the End of Compulsory Schooling, the Essential Learnings, disciplinary syllabi and programmes, citizenship frameworks, digital education guidance, and relevant decrees and policy notes issued by the Ministry of Education, Science and Innovation (MECI). From this corpus, we developed a deductive–inductive coding scheme covering the core dimensions of data literacy. In parallel, an online survey to teachers from grades 1–12, school leaders and specialist professionals was designed and administered. Sampling combined convenience and snowball approaches to secure diversity across regions, levels, and subjects. The instrument comprised sections on professional profile, conceptual understanding of data literacy, perceived readiness in knowledge and skills, current data use in pedagogy, assessment and school processes, attitudes and ethical concerns, perceptions of curricular integration and implementation conditions, as well as obstacles, supports, and examples of promising practices. Quantitative analyses were limited to descriptive statistics and group comparisons, reporting frequencies, measures of central tendency and dispersion, and between group differences by level of schooling, subject area, and role. Qualitative analysis applied thematic coding to open ended responses and policy texts, aligning categories with the data literacy framework and explicitly attending to ethical and justice related dimensions. Integration of the two datasets was achieved through joint displays juxtaposing curricular maps with participants’ perceptions and practices, which made visible convergences, tensions, gaps, and opportunities for improvement. The integrated synthesis underpinned actionable recommendations for policy, curriculum design, and teacher professional development, including organisational conditions. Ethical procedures included voluntary participation with informed consent, pseudonymisation, secure storage, and compliance with GDPR principles of data minimisation, confidentiality, and transparency.

The study produced an integrated account of how data literacy is positioned across Portugal’s compulsory education by combining curricular analysis with educators’ perceptions and practices. Documentary evidence showed system wide presence but uneven distribution of data related competencies, with clearer articulation in Mathematics, Sciences, and selected upper secondary pathways. Early childhood and primary education included data experiences—counting, organising information, simple surveys—yet often without explicit conceptual framing as “data literacy.” Cross disciplinary connections appeared in guidance and school level initiatives but lacked coherent progression across cycles. Survey results indicated that educators strongly valued data literacy for fostering critical thinking, informed citizenship, and resilience to misinformation. However, self reported preparedness was moderate: confidence tended to be higher in descriptive statistics and lower in visualisation, data storytelling, and ethical legal aspects. Practices were more established in assessment and internal monitoring than in student led inquiry or the use of authentic, locally sourced data in project based learning. Recurring barriers included limited time, scarce opportunities for interdisciplinary collaboration, uneven resource availability, and the absence of explicit assessment tools and progression criteria. Conversely, sustained professional development tied to authentic tasks, supportive leadership, collaborative structures and access to usable datasets and tools emerged as key enablers. Triangulating the strands revealed tensions between curricular ambition and teachers’ perceived readiness, uneven articulation of interdisciplinary work, and ambiguity over roles and responsibilities for addressing ethics, privacy, and data justice in everyday teaching. At the same time, the study documented promising practices—co teaching between subject teachers and school librarians, integration within environmental and citizenship education, student surveys, and the use of local media and open data to build statistical reasoning—illustrating feasible pathways for scaling.

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