In recent decades, science education has faced a persistent and widely acknowledged challenge: a lack of conceptual coherence stemming from overloaded curricula and the fragmented presentation of scientific topics. Such fragmentation limits students’ opportunities to develop deep, connected, and transferable understanding and can distance learners from science while hindering efforts to relate scientific ideas to real-life contexts (Harlen, 2010, 2015). In response, “big ideas” have been proposed as a conceptual framework for structuring science learning. Big ideas in science learning are the fundamental, generative, and explanatory concepts that help learners make sense of a wide range of phenomena within a coherent meaning system and across developmental time (Plummer & Krajcik, 2010; Perkins, 2014). Empirical research suggests that big-ideas-based curriculum design can strengthen both horizontal and vertical coherence, facilitate integration across scientific domains, and enhance student engagement (Bell et al., 2018; Chalmers et al., 2017), and that teachers may use big ideas to strengthen links between school science and students’ everyday experiences (Bravo & Reiss, 2021).

Despite this prominence, two gaps remain in the literature. First, there is still limited consensus regarding what constitutes a big idea and how its scope, boundaries, and criteria for identification should be defined (Siemon, 2022; Nosrati, 2025). Second, it remains unclear which features of big ideas are generalizable across educational contexts and which are shaped by cultural, structural, and curricular traditions within particular education systems (Nosrati, Talaee, Hatami, & Mehrmohammadi, 2025). Recent work suggests that overarching ideas can be framed through different disciplinary lenses for sense-making, reinforcing the need for comparative investigations of how big ideas are interpreted across educational ecosystems (De Boer, Janssen, Van Driel, & Dam, 2019). In the Dutch context, curriculum developments such as Curriculum.nu (2019) further underscore expectations for science teaching that combine conceptual understanding with societal relevance, illustrating how national frameworks may align with big-idea thinking.

Against this backdrop, the present study investigates how science education experts in two contrasting educational systems, Iran and the Netherlands, interpret and operationalize the Big Ideas of Energy, and how these interpretations relate to broader cultural, linguistic, and structural characteristics of the systems. The central research question guiding the study is: Which characteristics of big ideas and conceptual coherence are context-dependent, and which possess a more universal, cross-cultural nature? The study’s objectives are (a) to map expert conceptualizations of coherence in relation to Energy as a curriculum topic; (b) to identify convergences and divergences in how big ideas are understood as curriculum organizers across contexts; and (c) to generate implications for context-responsive curriculum design and implementation.

The theoretical framing positions big ideas as curriculum organizers that support conceptual coherence by connecting ideas within and across domains (Cartier & Pellathy, 2009; Plummer & Krajcik, 2010). Conceptual coherence is treated as learner-centered, acknowledging that what appears coherent to disciplinary experts may not necessarily support student understanding. The study also draws conceptual contrasts with Threshold Concepts to clarify the status of big ideas as organizers of learning progressions rather than gateways tied to individual conceptual transformation. Building on Nosrati’s (2025) typology, big ideas are approached through core features related to intradisciplinary and interdisciplinary coherence, while recognizing that their interpretation and implementation are mediated by local educational ecosystems (Nosrati, 2025).

This study adopts a descriptive–analytical and comparative design to examine how the Big Ideas of Energy are interpreted and operationalised in two educational contexts: Iran and the Netherlands. The dataset was generated through an online questionnaire completed by eight Iranian and six Dutch science education experts. Experts were recruited via purposeful sampling using equivalent criteria in both countries to ensure comparability. Selection criteria included professional experience in science education, physics education, curriculum design, or teacher education; documented expertise in teaching and/or curriculum development related to energy (e.g., textbook authorship or scholarly publications); recent involvement in curriculum initiatives or teacher professional development; and professional recognition evidenced through institutional roles, publication records, or nominations by senior experts. The study uses four Big Ideas of Energy as the analytical reference framework: (1) Energy is conserved and transforms when systems interact; (2) the amount of nergy available to any system is limited; (3) the quality and direction of energy transfer determine system outcomes; and (4) all living and non-living systems depend on a continuous flow of energy for survival, functioning, or growth. These Big Ideas, developed by Nosrati’s (2025), were validated through expert consensus, structured the questionnaire and the subsequent analysis. The questionnaire consisted of short, structured yet open-ended items designed to elicit reflective, conceptually rich responses while minimizing respondent burden. Items were developed based on the study’s conceptual model and addressed three analytical dimensions: Big Ideas of energy, intra- and interdisciplinary coherence, and contextual/cultural interpretation. Participants responded in Persian, English, or Dutch according to preference; all responses were translated into English for analysis. Translation quality was supported through review by proficient speakers, participant clarification of ambiguous phrases when needed, and reference to both original and translated texts in cases of interpretive uncertainty. Data were analysed using qualitative content analysis. Responses were read iteratively to identify conceptual patterns and context-dependent interpretations. Coding was guided by theoretically derived categories from the conceptual model while remaining interpretive. Analysis proceeded in two stages: within-context analysis for each country, followed by cross-context comparison to identify convergences, divergences, and culturally mediated interpretations. Rigour was strengthened through independent coding by two coders with iterative consensus-building, maintenance of an audit trail, use of direct quotations to ground interpretations, and reflexive memos throughout the analytic process. Ethical procedures included informed consent, anonymisation, and secure data storage with restricted access.

The study is expected to show how expert interpretations of the Big Ideas of energy are shaped by the cultural, linguistic, and structural characteristics of educational systems, and how conceptual coherence is pursued through different “implementation levers” across contexts. In the Iranian context, experts are expected to identify the core conceptual challenge of teaching Energy as the abstractness of content, weak coherence in textbooks, curriculum overload, and limited connections to everyday life; consequently, they tend to view Big Ideas primarily as a structural and organizational tool for curriculum design, emphasizing textbook coherence and deliberate sequencing as key levers for improving understanding. In the Dutch context, experts are expected to foreground linguistic and semantic ambiguity as the dominant barrier, particularly tensions between everyday and scientific meanings of “Energy”, and to emphasize scientific language, semantic precision, and model-based reasoning as essential conditions for conceptual coherence. Dutch experts are also expected to express more critical stances toward the current four-part Big Ideas framework, highlighting the need for clearer system boundaries, explicit attention to measurement-related principles, and greater conceptual precision. Across both contexts, the findings are expected to surface partially overlapping concerns (e.g., school–university discontinuities and the need for effective teaching approaches), while also revealing differences in what is treated as the primary driver of students’ interpretations. Iranian experts are expected to emphasize teacher-, textbook-, resource-, and assessment-related factors, whereas Dutch experts are expected to highlight broader socio-cultural and linguistic influences such as the home language environment and students’ everyday engagement with scientific ideas. Overall, the results are expected to support the claim that Big Ideas do not operate as fixed, universally transferable constructs; rather, they function as context-responsive frameworks whose effectiveness depends on culturally aligned implementation that combines internal conceptual integration with meaningful connections to real-life contexts.

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