Bridging Disciplines: Exploring Interdisciplinary Curriculum Development in STEM Teacher Education

Abstract

The global emphasis on interdisciplinary teaching continues to shape educational discourse, promoting meaningful and valuable learning experiences. This study examines the interdisciplinary curricular process led by a group of second-career teacher trainees and explores its role in shaping their emerging professional identities. The research focuses on eight high-achieving individuals transitioning to teaching as a second career through a STEM-focused (Science, Technology, Engineering, Mathematics) teacher preparation program. Employing a qualitative case study methodology, the study reveals a curricular process characterized by confusion and conflict as second-career teacher trainees navigate interdisciplinary integration. The findings highlight a planning process driven by conceptual and epistemic deliberations at both inter- and intra-disciplinary levels, with a predominant focus on disciplinary considerations over pedagogical aspects. The study further identifies key tensions that challenged participants’ perceptions, emotional responses, and instructional practices, offering a nuanced perspective on the complexities of interdisciplinary teaching. These insights contribute to a deeper understanding of professional identity formation among second-career teachers in STEM education.

1. Introduction

Interdisciplinarity is a guiding principle in global innovative teaching and learning design, aimed at fostering meaningful and impactful learning experiences. In the contemporary era, complex global challenges—such as climate change, pandemics, and technological innovation—necessitate a more holistic and comprehensive approach to teaching and learning. This approach aims to build learners’ general knowledge while nurturing independent, creative, and systems-based thinking. Integrating diverse disciplines allows for a deeper understanding of complex issues, as reality is not neatly divided into separate fields of knowledge. Consequently, interdisciplinary learning is relevant and connected to students’ everyday lives. Furthermore, interdisciplinary engagement emphasizes similarities and connections across various systems, promoting critical thinking, creativity, and the ability to solve multidimensional problems (Humes, 2013; Kneen et al., 2020). However, the ability to lead curricular processes that align with this principle poses significant challenges, both for experienced educators and especially for novice teachers. The concept of wicked problems in education (Sork, 2019; Kate et al., 2019) provides a useful lens through which to frame global challenges. Such problems are complex, interconnected, and resistant to straightforward solutions, thereby underscoring the value of interdisciplinary education

Despite the increasing emphasis on interdisciplinarity in policy and theory, actual implementation remains elusive. Curricula in schools and higher education institutions have largely remained discipline-based and fragmented, potentially resulting in a disconnection between fields of knowledge and a lack of relevance to students’ lives (Baybayon et al., 2018; Hughes et al., 2023). Moreover, there is a paucity of research that closely examines how prospective teachers—particularly those transitioning from content-expert roles—interpret, experience, and internalize interdisciplinary approaches during their preparation (Alrwaished, 2024).

One population for whom the call for interdisciplinary teaching is particularly pronounced includes mathematics and science educators. In recent years, there has been a global trend to promote STEM education to address the shortage of teachers, especially in science, mathematics, and engineering. Many teacher training programs recruit experts in these fields, preparing them to teach as a second career (Watters & Diezmann, 2015). These programs are often accelerated and brief due to the immediate demand. As a result, despite their extensive content knowledge, high motivation, and enthusiasm for imparting knowledge, research has shown that these teachers often face difficulties in effectively teaching and leading students during their initial stages (Boyd et al., 2011).

This raises important questions about how second-career STEM educators make sense of their evolving professional identity in relation to interdisciplinary teaching expectations. Prior studies have focused more on structural barriers to interdisciplinarity than on the cognitive, affective, and identity-related dimensions of the teacher preparation experience. Thus, there is a critical need to explore how these teachers perceive and enact interdisciplinarity during their preparation process.

To address this gap, the current study aims to shed light on the process of professional identity formation among second-career teacher trainees enrolled in a STEM-focused teacher education program by closely examining how they navigate interdisciplinary curriculum planning and effectively translate their extensive knowledge in mathematics and science for younger learners.

The present study responds directly to these complexities by examining how interdisciplinary curriculum work shapes professional identity among STEM teacher candidates. It aims to generate insights into how interdisciplinary training experiences are internalized, negotiated, or resisted, and how this process informs our broader understanding of STEM teacher preparation.

2. Conceptual Framework

2.1. Navigating Professional Identity

The professional identity of educators is a pivotal factor influencing teaching quality and student outcomes. Suarez and McGrath (2022) emphasize that a well-developed Teacher Professional Identity (TPI) enhances educators’ cognitive engagement and supports their professional growth. Chamo and Broza (2023) further explore the significance of TPI by examining how it enhances cognitive processes and fosters professional development. Their research underscores the importance of reflective practices and continuous learning in shaping a robust professional identity.

Olsen (2016) delineates analytical perspectives for examining teacher identity: psychological (focusing on individual identity), sociological (emphasizing collective identity), and socio-cultural (highlighting dialogical identity development). Hermans (2016) expands on the socio-cultural perspective through Dialogical Self -Theory, which posits that the self comprises a dynamic multiplicity of “I-positions” engaged in internal dialogues. This framework is particularly relevant for second-career teachers who must reconcile their previous professional identities with their new roles in education.

Second-career teachers often face the challenge of integrating their past professional experiences with the expectations of the teaching profession. This transition requires not only acquiring competencies expertise but also adapting to the unique culture and demands of the classroom. Effective teacher preparation programs must therefore focus on strengthening teachers’ commitment and agency. Bar-Tal et al. (2020) and van Heijst et al. (2025) advocate for training approaches that empower teachers to navigate these complexities confidently.

Research on teacher induction sheds light on the challenges and opportunities faced by second-career STEM teachers, particularly in shaping their emerging Teacher Professional Identity (TPI) (Kayan-Fadlelmula et al., 2022). Many career-changers enter the profession seeking meaningful work but often underestimate the pedagogical and classroom demands, which can diminish self-efficacy and disrupt identity formation (Williams, 2013; Zuzovsky & Donitsa-Schmidt, 2014). While “accelerated programmes” are referenced in the literature, they often reflect urgent leadership needs driven by global STEM teacher shortages rather than formal fast-track pathways. For example, Australia reports thousands of unfilled STEM teaching posts, with career-changers frequently stepping into leadership roles from the outset (NSW Department of Education, 2023). Across Europe, similar shortages have led to reliance on lateral entry and emergency staffing, placing new teachers in mentoring or coordination roles early in their careers (European Commission, 2023). Countries such as the UK, Germany, and Italy increasingly recruit professionals from industry or paraprofessional backgrounds to address these gaps (Euronews, 2022). International initiatives like the Erasmus+-funded NEST programme by Teach For All aim to support these transitions by combining structured induction with mentoring to strengthen TPI and self-efficacy (Teach For All, 2021). However, without adequate mentoring and targeted professional development, early leadership responsibilities may overwhelm new teachers and contribute to attrition. In England, the extension of the induction period from one to two years through the Early Career Teacher (ECT) programme, aims to scaffold identity development and improve retention. Evaluations of the Early Career Framework (ECF) indicate improvements in teaching confidence, mentor–mentee trust, and STEM pedagogical competence. Yet challenges persist, especially the increased workload and lack of STEM-specific training for both mentors and ECTs.

2.2. STEM, Interdisciplinary Learning, and Curriculum Planning

The need for resilience and adaptability is particularly salient in the context of STEM education, where interdisciplinary teaching requires educators to navigate complex content as well as differing epistemological approaches across disciplines. Each field within mathematics and science embodies a distinct body of knowledge. Mathematics is grounded in rules, axioms, proofs, and abstract reasoning, independent of empirical observation. In contrast, science relies on an empirical methodology involving experimentation, observation, and measurement of natural phenomena.

A central critique of mathematics education is its frequent overemphasis on rote memorization of rules and procedures, often at the expense of conceptual understanding. Researchers differentiate between conceptual knowledge, which involves a deep grasp of principles, and procedural knowledge, which refers to the execution of operations. Studies suggest that stronger conceptual understanding enhances procedural fluency (Rittle-Johnson & Siegler, 2022). In this context, Patkin and Plaksin (2019) found that engaging teacher trainees in challenging discussions, particularly those involving spatial perception in geometry, significantly improved their relational understanding and its application in practice. This builds upon Skemp’s (1976) influential framework, which contrasts instrumental understanding (rule-based application without comprehension) with relational understanding (awareness of underlying rationale), highlighting how these distinctions inform mathematical discourse among future educators.

Unlike multidisciplinary approaches that maintain disciplinary boundaries, interdisciplinary learning integrates ideas and modes of thinking across subject areas. Shulman (2013) underscores critical considerations in designing such curricula, including content selection, age-appropriateness, and the evolving role of the teacher. Socio-cultural theory also contributes to this perspective, viewing learning as a transformation of discourse that enables new knowledge construction (Sfard, 2019).

Effective interdisciplinary teaching requires educators to possess both deep disciplinary knowledge and robust pedagogical expertise (Humes, 2013; Winks & Warwick, 2021). Collaborative planning among educators can address gaps in content knowledge and foster professional growth (Baybayon et al., 2018; Hughes et al., 2023). However, meaningful integration is grounded in thoughtful curriculum planning (CP), a foundational element in teacher education programs worldwide (Flores, 2016). CP must also consider contextual factors that shape curriculum design (Luke, 2008).

STEM education encompasses all educational levels and seeks to reflect real-world complexities by integrating science, technology, engineering, and mathematics. An interdisciplinary STEM approach embeds one discipline within another—for example, integrating mathematics into scientific inquiry—to create meaningful intersections rather than superficial links. As the “language” of science, mathematics enables generalization, abstraction, and modeling (Chrysostomou, 2004), enhancing students’ understanding and fostering positive attitudes toward learning (Tytler et al., 2021). The COVID-19 pandemic further underscored the value of such integration in addressing real-world problems (Bakker et al., 2021).

This emphasis on real-life learning has been further supported by recent literature that positions STEM education as a vehicle for problem-based, project-based, and inquiry-oriented instruction grounded in authentic contexts (English, 2017; Margot & Kettler, 2019). English (2017) provides a comprehensive framework for integrating STEM that emphasizes authentic, student-centered learning experiences anchored in real-world challenges. Margot and Kettler (2019), through a systematic literature review, identify persistent obstacles and enablers in implementing STEM meaningfully, highlighting the need for pedagogical clarity and institutional support in K–12 settings.

Curriculum planning plays a pivotal role in structuring interdisciplinary learning by determining what content to integrate and how disciplinary connections are formed (Hughes et al., 2023). Defined as “a plan that has elements” (Cahapay, 2020, p. 1), curriculum design has traditionally followed Tyler’s (1949) four components: goals, content, pedagogical strategies, and assessment. Yet, contemporary approaches call for more flexible, dynamic models that support cross-disciplinary engagement (Zhao & Watterston, 2021). Recent models also emphasize curriculum as a dynamic system responsive to global, cultural, and ecological challenges (Chesky & Wolfmeyer, 2015).

Aktan (2021) revisits earlier systematic curriculum models (e.g., Bobbitt, 1918; Tyler, 1949) and highlights Dewey’s enduring emphasis on experiential learning. In line with these principles, interdisciplinary curricula should not only merge disciplinary content but also align with real-world challenges, encouraging critical thinking and problem-solving. Pinar (2003) expands this vision, framing curriculum as a means for students to reflect on the world they are inheriting, thus preparing them to engage thoughtfully with an increasingly interconnected society. Integrative STEM models such as those proposed by Vasquez et al. (2020) and Kelley and Knowles (2016) also emphasize the role of teacher-facilitated inquiry and cross-disciplinary fluency in supporting student learning through authentic, applied contexts.

Recent empirical studies further demonstrate the importance of professional development in supporting STEM integration. For example, Mohamad Hasim et al. (2022) show how targeted STEM PD enhances teachers’ instructional practices and knowledge alignment. Additionally, Retno et al. (2025) propose a conceptual model for project-based STEM learning (PjBL-STEM) tailored for elementary education, offering a structured framework to guide interdisciplinary curriculum design.

Meta-analyses indicate that integrated STEM programs enhance academic performance, student engagement, and satisfaction (Novis-Deutsch et al., 2024). Hands-on applications, such as experimental tasks, support deeper mathematical understanding (Baybayon et al., 2018), while higher education innovations—like interactive simulations in chemistry and physics—further reinforce the connection between conceptual learning and real-world application (Hughes et al., 2023; Kaldaras & Wieman, 2023). Ultimately, linking interdisciplinary learning with curriculum planning enables educators to design cohesive and relevant educational experiences that prepare students for navigating complex, authentic problems.

2.3. Challenges in Designing Interdisciplinary Math and Science Learning

Although interdisciplinary approaches to STEM education are widely recognized for their benefits, several persistent barriers continue to hinder effective integration. Key challenges include insufficient disciplinary expertise, gaps in pedagogical content knowledge, and limited professional support for both the planning and implementation of integrated lessons. Recent studies from Korea, Indonesia, and China (e.g., Kartini & Widodo, 2020) identify two central issues constraining interdisciplinary curriculum planning: (1) teachers’ low sense of self-efficacy, and (2) the absence of planning frameworks that allocate sufficient time and resources for collaborative curriculum development. These findings underscore the broader issue of inadequate training and professional development in this domain. In alignment with these concerns, Margot and Kettler (2019), in their systematic review, highlight similar patterns across Western contexts, noting that while teacher enthusiasm for STEM integration is often high, the lack of pedagogical clarity and sustainable support structures remains a key impediment.

A common misinterpretation among educators is viewing STEM education as a series of disconnected activities rather than as a cohesive, inquiry-driven or project-based pedagogical model (Zell, 2019). This misconception poses a major barrier to integration, as interdisciplinary learning demands a fundamental shift in instructional approach. Teachers must move away from traditional, directive methods and adopt facilitative roles that support student-led inquiry and exploration (Boice et al., 2021). Capraro et al. (2013) emphasize that project-based learning within integrated STEM contexts requires intentional design, cross-disciplinary coordination, and active learning environments that reflect real-world problems. English (2017) likewise emphasizes that authentic integration must move beyond surface-level connections and be grounded in contextual problem-solving that mirrors how disciplines operate in real-world settings. Such approaches necessitate professional development and structural support to ensure sustainability and pedagogical coherence.

Another significant challenge relates to disciplinary hierarchies and perceived power dynamics. Within integrated STEM lessons, mathematics is often subordinated to science, raising concerns within the mathematics education community. Typically, science provides the thematic context and conceptual content, while mathematics plays a supporting, procedural role—used primarily for measurement, data collection, or simple calculations (Williams & Roth, 2019). This imbalance means that mathematics often “follows” science rather than standing as an equal partner in interdisciplinary learning. As a result, students may become proficient in applying mathematical procedures but lack opportunities to engage deeply with mathematical reasoning or develop advanced problem-solving skills.

The predominance of science learning objectives in interdisciplinary settings is further reinforced by the tendency for integration initiatives to be led by science teachers rather than mathematics teachers (Hughes et al., 2023). According to Humes (2013) and Winks and Warwick (2021), this leadership imbalance may stem from mathematics teachers’ limited content knowledge in science, which can create uncertainty or reluctance to engage in collaborative planning. However, knowledge gaps can exist in both directions—i.e., mathematics teachers may have limited science knowledge and vice versa. This mismatch in disciplinary confidence can also lead to professional tensions and conflicts during curriculum development (Coleman, 2018; Hayes & Doherty, 2017).

Recent research points to the critical role of targeted professional development in overcoming these barriers. For instance, Mohamad Hasim et al. (2022) found that STEM-focused PD can significantly improve teachers’ content knowledge and instructional coherence, thus increasing confidence in interdisciplinary planning and execution. Building on this, Retno et al. (2025) propose a conceptual framework for STEM-integrated project-based learning (PjBL-STEM) that provides scaffolding for curriculum design and pedagogical implementation, particularly at the elementary level. This model offers a systematic approach to integrating disciplines through authentic, problem-based tasks, addressing both epistemic uncertainty and instructional fragmentation.

These findings point to underlying structural and epistemic challenges that can complicate collaborative teaching efforts in STEM education. Chesky and Wolfmeyer (2015) advocate for an ecojustice-oriented model that foregrounds equity, teacher agency, and contextual responsiveness—critical considerations often missing from top-down integration mandates. In response, Wang et al. (2011) emphasize the need to understand teachers’ actual perceptions and classroom practices around integration, highlighting the gap between policy aspirations and practical implementation. This reinforces calls for systemic efforts to reframe interdisciplinary collaboration as a shared endeavor grounded in mutual respect for disciplinary knowledge, adequate co-planning time, and a common pedagogical vision (Wang et al., 2011; Kelley & Knowles, 2016).

2.4. Research Context

This study is situated within the context of teaching and learning in a course focused on fundamental principles in the science of learning: teaching, learning, and assessment. This is a foundational course designed to instruct second-career teacher trainees in the way they are expected to teach meaningful learning processes and be able to conceptualize them within the theoretical frameworks they are exposed to. The participants in this study were teacher trainees, some of whom specialized in science education and others in mathematics education.

To achieve this, the course is structured according to the Challenge-Based Learning Model (CBL) (Leijon et al., 2022). Challenge-Based Learning is defined as a pedagogical approach that promotes active learner engagement, collaborative inquiry, and real-world relevance. It emphasizes critical thinking, community building, and ongoing assessment (Bransford et al., 2000). At the heart of this process lies the principle that learning should be driven by curiosity and motivation, facilitated through interdisciplinary learning within contexts relevant to students and their communities. While CBL was originally developed through Apple Education initiatives to align technology with authentic, student-driven learning, subsequent adaptations such as those advanced by Digital Promise have expanded the model beyond its commercial origins to emphasize equity, open-ended inquiry, and educational transformation (Digital Promise, 2021).

CBL

The challenge presented in the course involves the development of an interdisciplinary teaching unit based on the constructivist theory in mathematics and science, centered on the scientific principle of the surface area-to-volume ratio. This concept describes the relationship between the structure and function of a body. More specifically, as a body decreases in size, its surface area-to-volume ratio increases, which in turn leads to higher rates of material exchange with the surrounding environment. Furthermore, the shape of a body influences changes in this ratio—meaning that a flattened or protruding body has a higher surface area-to-volume ratio compared to a spherical body of the same volume.

Against the backdrop of the overarching challenges presented in the research literature on the formation of professional identity among students transitioning into teaching in the fields of science and mathematics, and in light of the specific difficulties and challenges associated with designing interdisciplinary teaching, the need for in-depth research becomes increasingly evident. This study aims to explore the dual challenge of identity formation and interdisciplinary design faced by the current research group in leading interdisciplinary curricular planning and, consequently, to understand the processes shaping their emerging identities as new educators.

Therefore, the research questions are:

• What conceptual and practical challenges do second-career STEM teacher trainees encounter when designing interdisciplinary teaching units?
• In what ways does the process of interdisciplinary curriculum planning contribute to the formation of professional identity among second-career STEM teacher trainees?

3. Methodology

The research approach is qualitative-interpretative (Creswell & Poth, 2016), employing a case study method that enables an in-depth examination of a complex and holistic phenomenon within a specific context (Poth, 2016). Case study research is characterized by its focus on a particular event, group, or phenomenon, involving detailed observation and data collection from multiple sources. This method facilitates an understanding of the complexity of the studied case by addressing various contextual dimensions (Yin, 2014).

In this study, a qualitative case study approach was chosen to explore group dynamics and professional identity development among eight mathematics and science second-career teacher trainees. The specific educational task and pedagogical aims justified the researchers’ active positioning within the context, consistent with case study principles (Yin, 2014). The second researcher’s dual role as lecturer and pedagogical instructor—while a potential source of bias—was explicitly acknowledged and addressed. Transparency with participants, peer debriefing, and data triangulation were used to mitigate bias. In particular, the second researcher maintained detailed field notes throughout instructional and observational sessions, which served as both a reflexive tool and a source for validating interpretations. These steps contributed to the credibility and trustworthiness of the research process.

3.1. Research Participants

The study involved eight second-career teacher-seven males and one female—all between the ages of 35 and 50 trainees who were distinguished professionals in their respective fields and were trained through special program, which promotes the training of mathematics and science experts for secondary school teaching. All of them chose education as a second career and agreed to participate in the study over the course of one academic year. They consented to having certain discussions—held at the beginning, middle, and end of the year—recorded and transcribed in order to understand the processes occurring within the group in relation to the development of an interdisciplinary unit. The second researcher in this study also served as the group’s lecturer and pedagogical instructor.

The participants were divided into two groups based on their area of expertise according to the college formal program: four specializing in mathematics and four in science. These subgroups were intentionally created during the early phase of the course to scaffold disciplinary grounding, before the participants moved into interdisciplinary collaboration. Ultimately, the eight participants formed a single interdisciplinary team. The group collaborated in developing an interdisciplinary teaching unit that integrated mathematical and scientific knowledge as part of their professional training. The selection of these participants was driven by the desire to understand how trainees from different disciplines collaborate, learn from each other, and contribute to shaping their professional identities. Together, the eight mathematics and science trainees formed a single team tasked with developing an interdisciplinary teaching unit on the surface area-to-volume ratio.

3.2. Research Instruments

The study employed three primary data collection tools: documents, interviews, and field notes.

Documents: Drafts developed by the group served as a central data source. These documents included planning stages, consultations, and modifications made to the teaching unit during the collaborative work process. They provided insights into group dynamics and the individual contributions of each participant to the development process.

Participant Interviews: Interviews were conducted through guided group discussions, facilitated by the second researcher. Participants were purposefully selected based on their involvement in the interdisciplinary unit, ensuring a range of relevant perspectives. The eight participants were divided into two groups according to their area of expertise: one group of four mathematics specialists and another of four science specialists. Each discussion lasted approximately 90 min. A semi-structured interview guide was used to direct the conversations, focusing on participants’ roles and experiences within the group, challenges encountered in interdisciplinary collaboration, expectations for the unit’s outcomes, and suggestions for improvement. This format encouraged open dialogue while maintaining consistency across sessions. The group setting enabled participants to reflect collaboratively, resulting in a deeper understanding of individual and collective perceptions, expectations, and internal processes.

Field Notes: The course instructor, who is also one of the researchers, documented observations throughout the academic year. These notes included reflections on actions, dilemmas, and various vignettes from the course, offering additional context for understanding the research process.

3.3. Data Analysis

The data analysis followed a thematic analysis approach (Braun & Clarke, 2006; Nowell et al., 2017), focusing on identifying patterns and key themes emerging from the collected data. The process included four main stages:

Initial Immersion: A thorough review of documents and interviews to identify central ideas and gain an overall impression of the data.

Open Coding: Generating initial codes across the dataset to capture significant features of the data relevant to the research questions.

Theme Development: Codes were examined and grouped into key themes, such as interdisciplinary collaboration, professional identity development, and group decision-making processes. These were further organized into broader categories informed by the literature on teachers’ professional identity and curriculum planning.

Validation and Refinement: The themes were reviewed and refined by revisiting the original data, checking for consistency, and strengthening interpretations through illustrative examples and emerging insights. Peer debriefing within the research team supported the credibility of the analysis.

3.4. Ethical Considerations

Principles of anonymity and confidentiality were maintained, and participants provided informed consent after completing their studies and when no hierarchical relationship existed between them and the researcher. It was also clarified that course materials would be used to deepen understanding of their identity formation processes and remain accessible to them—aligned with the principles of a “covenantal ethics” approach. The entire process was reviewed and approved by the ethics committee of the academic institution where the researchers are affiliated and where the study was conducted.

4. Findings

This section presents six themes that emerged from the analysis of collaborative curriculum planning among second-career STEM teacher candidates. These themes illuminate both the conceptual and practical challenges encountered in designing interdisciplinary teaching units, as well as the ways in which these collaborative processes intersected with participants’ evolving professional identities.

The findings are structured thematically rather than divided strictly by research question, in recognition of the conceptual entanglement between RQ1 (which examines the barriers and affordances involved in interdisciplinary design) and RQ2 (which explores how this process shapes professional identity). In the lived experience of participants, these two dimensions unfolded simultaneously. Therefore, rather than artificially separating them, the themes reflect how tensions in curriculum design and moments of epistemological uncertainty often served as triggers or catalysts for identity negotiation. The first three themes—epistemological ambiguity, pedagogical dissonance, and disciplinary communication gaps—are closely aligned with Research Question 1, which explores the barriers and tensions second-career teacher trainees face in integrating disciplinary perspectives into coherent teaching units. The remaining themes—negotiation of curricular coherence, role redefinition in collaborative settings, and emergent ownership of interdisciplinary practice—speak more directly to Research Question 2, revealing how the act of planning across disciplinary boundaries served as a space for constructing and reshaping professional identities. However, the boundaries between these two sets of themes are intentionally porous, as many insights span both conceptual domains. Together, these themes offer a comprehensive view of how second-career teachers navigated the intersection of disciplinary knowledge, teaching practice, and identity development.

The first theme, epistemological ambiguity, was especially evident in the participants’ initial responses to the interdisciplinary task. The research participants expressed feelings of embarrassment and exhibited a low sense of self-efficacy regarding their ability to design an interdisciplinary teaching unit. While they did not voice explicit resistance, they also showed limited enthusiasm or support for the frameworks and pedagogical demands that underpin interdisciplinary teaching and learning.

In field notes documenting the mentoring process, the course instructor observed:

“Today, when I presented the assignment and its underlying rationale, a brief silence fell over the room. Typically, this is a lively and assertive group that frequently asks questions and responds actively.”

During the mediation of the assignment, participants asked questions that reflected a preference for a multidisciplinary approach, one that maintains disciplinary boundaries, rather than a fully integrated interdisciplinary model. For instance, Student D. inquired:

“Should we first introduce the fundamental concepts in mathematics and then…?”

This question reflects a linear understanding of learning and suggests a leaning toward behaviorist teaching practices.

Although students attempted to make connections between the content and real-life contexts, the relevance of these links often remained superficial. The course instructor further noted:

“It seems that in moving from the conceptual stage to practical planning, both teams exhibit non-constructivist perspectives and rely on traditional models of teaching focused on transmission and practice. This occurs despite having previously engaged with examples of interdisciplinary and multidisciplinary teaching units earlier in the course.”

These early instructional responses revealed and intensified two primary forms of conceptual ambiguity:

• Interdisciplinary ambiguity: uncertainty regarding the nature of the relationships and integration between disciplines.
• Intra-disciplinary ambiguity: uncertainty surrounding core understandings within individual disciplines.

4.1. Interdisciplinary Ambiguity

4.1.1. Hierarchical Conflict

Developing an interdisciplinary teaching unit requires not just the combination of content from multiple disciplines, but the integration of disciplinary ways of thinking and conceptual frameworks. Unlike multidisciplinary approaches, where each subject retains its autonomy, interdisciplinary work challenges educators to find meaningful connections that transcend disciplinary boundaries. One of the central tensions that emerged in this study revolved around the perceived hierarchy between mathematics and science—specifically, which discipline would lead the unit and frame the overarching inquiry.

In early discussions, the mathematics team proposed “patterns” as the central theme, focusing on natural occurrences of mathematical structures such as the Fibonacci sequence”. They argued that “highlighting how these sequences manifest in nature (e.g., in the number of petals on flowers or spirals in pinecones could deepen students’ understanding of sequences and mathematical structure)”.

Conversely, the science team suggested focusing on the concept of the surface area-to-volume ratio. Their rationale was “that this principle is foundational in biology and illustrates how mathematical knowledge can enhance the understanding of scientific phenomena. This ratio influences essential biological processes and structures, such as those found in cells, human physiology, and ecological systems”. From their perspective, “mathematics should be used to support conceptual development in science, particularly in areas students often find abstract or difficult when taught procedurally”.

This difference revealed a hierarchical conflict. Each team implicitly positioned its discipline as primary. The mathematics team sought to highlight mathematics through meaningful natural examples, whereas the science team aimed to use mathematical procedures in service of deeper scientific understanding. This disciplinary tension was explicitly voiced: the mathematics team argued that the topic proposed by the science team was “narrow and technical”, requiring only basic application of known mathematical definitions. In contrast, the science team asserted that the real pedagogical richness lay in helping students use mathematics to uncover misconceptions and grasp scientific ideas.

Despite these differences, the mathematics team eventually agreed to proceed with the science team’s proposal, justifying the choice by “emphasizing the growing educational consensus that mathematics gains meaning when embedded in relevant contexts.” The teams jointly formulated the unit goal and wrote:

“To explore and investigate the topic independently in different contexts, to analyze and explain scenarios using the principle, and finally, to apply the principle in new contexts.”

Although the science-led framing might suggest a hierarchical resolution, the justifications provided by both teams ultimately reflected an integrative stance. Mathematics was no longer viewed solely as a technical tool but rather as a language for formulating scientific arguments and making predictions in authentic contexts. The process marked a shift from discipline-centered planning toward a more balanced interdisciplinary approach.

4.1.2. Language Conflict: Symbolic vs. Semantic

A second source of tension emerged from disciplinary differences in the language used to describe key concepts, particularly the term “ratio”. While this issue initially appeared to be a technical one, it quickly revealed deeper epistemological differences between the disciplines.

The mathematics team drew on the curriculum, where “ratio” is defined as “a comparison of two quantities with the same units (e.g., the ratio of boys to girls in a class, or a scale on a map)”. These uses reflect a symbolic and static understanding of ratio, often presented as a fraction or quotient with no associated unit.

In contrast, the science team used “ratio” to describe “dynamic relationships between different units such as surface area (cm²) and volume (cm³), or speed (distance/time)”. This interpretation aligns more closely with the concept of rate, which expresses functional relationships found in natural systems and physical processes, such as density or fuel efficiency.

This semantic divergence led to conceptual confusion and a temporary impasse in the teams’ discussions. The mathematics team initially expressed concern “that this interpretation of ratio extended beyond the scope of the standard curriculum”. The facilitator intervened by encouraging both teams to consult the professional literature and examine the multiple meanings of ratio across disciplines. Here are some of the results pointed out by the mathematic team in their progressed draft:

“Drawing on Freudenthal’s (1986) distinction between RATIO (comparisons with identical units) and RATE (comparisons involving different units), the teams began to reconsider their approach. In Hebrew, as in some other languages, the lack of separate terms for “ratio” and “rate” exacerbates this confusion. The mathematics team revisited the national curriculum and found that it primarily includes the RATIO concept—used in contexts such as similarity, probability, and slope. In contrast, scientific inquiry often requires understanding RATE-type ratios, which are foundational for interpreting real-world data and modeling systems.”

This shared exploration led both teams to enrich the teaching unit by including a progression from mathematical representations of RATIO (e.g., with cubes and geometric figures) to scientific applications involving RATE (e.g., lung surface area, food volume, or body structures). In the final planning phase, the teams emphasized the need to “explicitly distinguish between these interpretations in classroom instruction and to highlight the role of density and other RATE-related concepts in scientific reasoning”.

This process illustrates how interdisciplinary collaboration can surface not only disciplinary hierarchies but also epistemological and linguistic challenges that must be addressed for true integration to occur. Ultimately, these tensions became productive, pushing both teams to broaden their pedagogical and conceptual understanding and to co-develop a richer, more nuanced teaching unit.

4.2. Intra-Disciplinary Ambiguity

Substantive conflicts refer to the perceptions revealed by the participants regarding the major structures of meaning within different fields of knowledge—mathematics, science, and pedagogy. During the discussion between the two teams about translating the content into a teaching approach (pedagogy), the question arose of how to integrate the key mathematical concepts into the scientific narrative, each separately (What is a ratio? What is surface area? What is volume?). After the discussions, the teams were required to formulate the rationale in writing. The mathematics team wrote:

“In mathematics, the focus is on understanding the relationships between geometric magnitudes through the use of formulas (A = surface area; V = Volume).

$${A=a}^2\times 6\to \hspace{1em}V=a^3\to \hspace{1em}{\displaystyle \frac{A}{V}}={\displaystyle \frac{6a^2}{a^3}}={\displaystyle \frac{6}{a}}$$

It is important for students to understand mathematical conclusions: the smaller the side a, the greater the ratio, and the larger the side, the smaller the ratio.

This reflects an inverse relationship between the dimensional size of the object and the ratio between surface area and volume. The mathematical objective is to develop an understanding of how this ratio changes when the size of the object changes and to generalize this understanding to other three-dimensional objects (e.g., cylinder, sphere, cuboid, etc.).”

The science team wrote:

“In science, we will examine the physical/biological implications of the change in the surface area to volume ratio. For example:

1. Biology—Cells:

Smaller cells can perform metabolic exchanges more efficiently because they have a relatively larger surface area to volume ratio.

Therefore, cells do not grow beyond a certain size, they divide.

2. Chemistry/Physics—Reaction of materials:

A block of iron versus iron powder: the powder has a much larger surface area relative to its volume and therefore reacts more quickly.

This explains why aluminum powder can be highly flammable.

3. Engineering—Cooling of objects:

Cooling fins (as in computers or engines) are designed to increase surface area to efficiently dissipate heat.

It is important for us that students understand why this is important in the real world and how this phenomenon affects biological, chemical, and engineering processes.”

Table 1. Epistemological and Pedagogical Contrasts Between Mathematics and Science Unit Plans.

Dimension	Mathematics	Science
Central Focus	Abstract relationships and structural patterns	Real-world phenomena and their implications
Driving Question	Quantitative comparison: What is the surface area to volume ratio?	Causal reasoning: Why does the surface area to volume ratio matter?
Mode of Representation	Symbolic language (e.g., formulas, variables, functions)	Descriptive and visual language with use of physical models
Instructional Tools	Equations, proofs, graphs, generalizations	Hands-on experiments, observations, simulations
Knowledge Orientation	Deductive and axiomatic; emphasizes logical necessity	Inductive and empirical; emphasizes explanatory reasoning
Cognitive Demand	Applying known rules to solve problems and construct generalities	Interpreting data, reasoning from evidence, constructing cause-effect links
Learning Goals	Procedural fluency and conceptual generalization	Scientific literacy and understanding of applied processes

summarizes the key epistemological and pedagogical contrasts that emerged during the process of deepening disciplinary understanding within mathematics and science. It serves as a diagnostic framework for identifying sources of intra-disciplinary ambiguity and provides a foundation for analyzing the interdisciplinary tensions and negotiation processes elaborated in

Table 2. Key Themes, Challenges, and Collaborative Processes in Interdisciplinary Unit Design.

Theme	Challenges Identified	Collaborative Processes and Responses
1. Emotional and Cognitive Readiness	- Low self-efficacy and embarrassment around interdisciplinary teaching. - Superficial enthusiasm and passive resistance to pedagogical change.	- Instructor-mediated space for questioning and reflection. - Gradual shift from passivity to engagement through structured tasks and instructors’ support.
2. Preference for Multidisciplinary over Interdisciplinary Approaches	- Tendency to retain disciplinary boundaries. - Linear, behaviorist planning tendencies despite exposure to alternative models.	- Facilitated discussions on integration vs. juxtaposition of content. - Use of reflective questioning to surface underlying assumptions.
3. Interdisciplinary Ambiguity: Disciplinary Hierarchies	- Implicit conflict over which discipline should “lead” the unit (math vs. science). - Perception of certain topics as more pedagogically “rich.”	- Considering a shared goal for the unit - Reframing of mathematics as a language for scientific reasoning. - Movement from disciplinary competition to conceptual integration.
4. Interdisciplinary Ambiguity: Language and Epistemology	- Confusion over the term “ratio” (symbolic vs. functional meanings). - Different interpretations due to curricular definitions and linguistic limitations.	- Collaborative inquiry into curriculum and literature (e.g., Freudenthal’s distinctions). - Agreement to incorporate both RATIO and RATE interpretations explicitly. - Emphasis on semantic clarity in classroom instruction.
5. Intra-disciplinary Ambiguity: Conceptual Foundations within Disciplines	- Difficulty articulating key disciplinary concepts in pedagogical terms. - Disconnection between content expertise and classroom application.	- Expanding information sources through engagement with research literature and critical reading of the curriculum. - Comparison of disciplinary ways of knowing (abstract vs. applied).
6. Epistemological Tensions between Mathematics and Science	- Differing views on what counts as valid knowledge: - Mathematics: deductive, structural, procedural. - Science: inductive, causal, contextual.	- Constructive conflict led to mutual accommodation. - Use of contrasting rationales to deepen understanding. - Integration of inquiry-based pedagogical and curricular approaches.

.

The differences in the teams’ formulations reveal underlying epistemological gaps between the disciplines regarding what constitutes valid knowledge in science and mathematics. The mathematics team’s perspective was grounded in an instrumentalist view of mathematical knowledge, emphasizing definitions, the precise use of mathematical language, and the application of procedures, particularly through formulas. Their focus remained on explicit concepts and computational skills, with limited attention to how changes in scale, proportion, or quantity might influence the structure or function of a system. This focus persisted even though the team initially expressed a desire to teach mathematical concepts in meaningful, contextualized ways.

In contrast, the science team adopted an inquiry-based epistemology, where scientific understanding emerges through the generation of hypotheses and their testing via empirical investigation. This approach reflects a process-oriented view of learning, where meaning is constructed through exploration and experimentation. From this standpoint, mathematics was treated primarily as a supporting tool, valuable for enabling access to scientific content but not central in itself. The science team’s emphasis on causal reasoning and the question of why appeared to promote relational thinking, in contrast to the mathematics team’s approach, which centered more on procedural knowledge and the retrieval of established rules and formulas.

Table 2 synthesizes the six emergent themes by mapping specific conceptual and practical challenges (left column) alongside the corresponding collaborative responses or mediations (right column) observed during interdisciplinary planning. This summary highlights how intra-disciplinary tensions, such as epistemological ambiguity and pedagogical misalignment, evolved into moments of negotiation and redefinition. In doing so, the table illustrates how the process of curriculum design not only exposed the complexity of integrating disciplinary perspectives (Research Question 1) but also served as a catalyst for professional identity development among second-career STEM teacher candidates (Research Question 2).

Collectively, the six themes offer a nuanced account of the challenges and learning processes that characterized interdisciplinary curriculum design among second-career STEM teacher candidates. The findings reveal that moments of disciplinary conflict and ambiguity were not merely obstacles but also opportunities for reflection, negotiation, and growth. Participants grappled with unfamiliar teaching paradigms, disciplinary language, and role expectations—experiences that prompted critical engagement with their own assumptions and beliefs about teaching and learning. Importantly, the collaborative nature of curriculum planning functioned as a catalyst for professional identity formation, enabling teacher candidates to test, revise, and gradually consolidate their emerging sense of professional self within interdisciplinary frameworks. These findings provide direct responses to the study’s research questions by illustrating both the multifaceted challenges of interdisciplinary curriculum design and its generative potential in shaping the identities of future STEM educators.

5. Discussion

This discussion addresses the two guiding research questions:

(1)

What conceptual and practical challenges do second-career STEM teacher trainees encounter when designing interdisciplinary teaching units?

(2)

In what ways does the process of interdisciplinary curriculum planning contribute to the formation of professional identity among second-career STEM teacher candidates?

The findings of this study reveal that designing interdisciplinary units in mathematics and science presents challenges that extend beyond content integration, surfacing tensions between disciplinary epistemologies, pedagogical norms, and evolving constructs of teacher professional identity (TPI). Participants’ efforts to reconcile these tensions reflect both the complexity of interdisciplinary teaching and the demands it places on their existing beliefs, roles, and instructional habits.

At the outset of the design process, most participants gravitated toward a multidisciplinary approach, juxtaposing disciplinary content without deep integration. This tendency aligns with their expressed need for conceptual security and a preference for maintaining established instructional practices. Drawing on Jacobs (1989) and Beane (1997), we define multidisciplinary as the coexistence of separate disciplinary contributions within a common theme, while interdisciplinary refers to the integration of knowledge, methods, and language across domains. The observed preference for the former, as documented in Theme 2 (Table 2), should not be interpreted as resistance, but rather as a strategic response to epistemological ambiguity and identity-related discomfort.

Two types of conflict emerged during the curriculum design process: hierarchical and linguistic. The hierarchical conflict reflected participants’ disciplinary attachments. Mathematics teachers, in particular, resisted repositioning their subject as a supporting element within a scientific inquiry. This resistance, evident in planning conversations and reflective discussions, points to a protective stance rooted in professional identity. As Beijaard et al. (2004) suggest, teachers’ professional identity is deeply connected to their subject-matter expertise and the pedagogical roles they adopt. When interdisciplinary collaboration required mathematics to serve science’s conceptual objectives, mathematics teachers expressed discomfort with what they perceived as a loss of disciplinary autonomy.

The linguistic conflict highlighted divergences in how disciplinary terms and modes of explanation were used. For example, mathematics teachers defined rate in static, quantitative terms, while science teachers approached it as a dynamic, causal construct linked to real-world phenomena. These differences illustrate more than mere terminology, they reflect distinct epistemological assumptions and discursive norms, as captured in Table 1. These findings support earlier studies emphasizing the need for epistemic fluency in integrated STEM instruction (English, 2017; Sfard, 2019; Retno et al., 2025).

In response to the second research question, evidence suggests that the process of interdisciplinary curriculum design prompted initial shifts in participants’ professional identities. These shifts were observable through changes in language, teaching roles, and collaborative behaviors (Theme 6, Table 2). However, identity reconstruction was not linear or uniform. While some participants began to embrace hybrid instructional roles, others maintained clearer disciplinary boundaries. This finding echoes Eteläpelto et al. (2015), who argue that identity transformation in professional contexts occurs through complex, socially mediated processes. Similarly, Kneen et al. (2020) highlight the importance of boundary crossing as a stimulus for pedagogical reimagining.

It is important to differentiate between challenges encountered and those meaningfully addressed during the intervention. Several issues, such as divergent discursive practices and unfamiliarity with integrative planning, were partially mitigated through collaborative tasks and instructor-facilitated reflection. Others, particularly epistemological misalignments and deeply held assumptions about disciplinary hierarchy, remained unresolved. Table 2 outlines these distinctions, summarizing the extent to which each theme was engaged through the intervention.

A critical reflection on the instructional design itself reveals that certain facilitation choices may have shaped the challenges observed. In particular, the initial decision to have participants work within disciplinary teams helped reinforce content confidence but inadvertently delayed opportunities for cross-disciplinary negotiation. This insight suggests that professional development programs should consider staging interdisciplinary collaboration earlier in the learning process to avoid entrenching disciplinary silos.

Despite the structured nature of the intervention, participants frequently defaulted to behaviorist teaching strategies—linear sequencing, direct instruction, and content coverage. While they demonstrated awareness of interdisciplinary principles, they struggled to enact them in practice. This gap reflects the difference between instrumental and relational understanding (Skemp, 1976) and suggests that developing interdisciplinary competence requires more than conceptual exposure, it demands pedagogical transformation supported by reflective guidance (Patkin & Plaksin, 2019).

Emotional dimensions of the design process were also significant. Documented moments of silence, hesitation, and limited engagement, especially during initial task mediation, indicate the presence of anxiety and uncertainty. These affective responses align with literature emphasizing the emotional labor of curricular innovation (Aktan, 2021; Cahapay, 2020). They also reinforce the need for teacher education programs to create safe, dialogic spaces for exploring discomfort and surfacing implicit beliefs.

The findings further suggest that interdisciplinary curriculum development serves not only as a technical activity but also as a context for identity negotiation. Professional development must therefore extend beyond content integration to include structured opportunities for reflection, modeling, and mentorship. Mohamad Hasim et al. (2022) emphasize that teachers’ epistemological awareness and instructional flexibility are strengthened through sustained professional learning activities. Likewise, Suarez and McGrath (2022) argue that identity development is central to pedagogical change and must be explicitly supported in teacher education programs.

Limitations: While this study offers valuable insights into group dynamics and interdisciplinary curriculum development, several limitations should be acknowledged. The small and demographically homogeneous sample—marked by limited female representation and distinct career trajectories—restricts the external validity of the findings. Although the in-depth qualitative approach provides rich, context-specific understanding, the transferability of results to other populations or settings may be limited. As a single-case study, the aim is not statistical generalization but analytical depth (Flyvbjerg, 2006), offering nuanced insights into complex educational processes. To enhance the robustness and applicability of these findings, future research should employ multi-case designs with more diverse participant profiles and varied institutional contexts.

6. Conclusions

This study advances our understanding of how second-career STEM teacher candidates engage with the challenges of interdisciplinary curriculum design. The findings highlight that such engagement extends beyond instructional technique—it involves negotiating epistemological beliefs, collaborative practices, and evolving professional identities. Early interdisciplinary teaming emerged as a key condition for fostering these processes, offering opportunities to build shared pedagogical goals and epistemic awareness. As STEM education increasingly demands cross-disciplinary fluency, preparing teachers to navigate these spaces must become an intentional component of teacher education. This includes structured reflection, sustained mentorship, and emotionally attuned support systems that enable teachers to internalize interdisciplinary practices as part of their professional identity.