Project-Based Learning as a Catalyst for Integrated STEM Education

1. Introduction

The call for enhancing Science, Technology, Engineering, and Mathematics (STEM) education to prepare students for tackling complex global challenges has become increasingly urgent (Becker & Park, 2011; Contribution 1; English, 2016; Contribution 7; Sokolova et al., 2025). Addressing these issues require not only deep disciplinary knowledge but also the ability to integrate multiple perspectives across fields and apply this level of understanding in real-world contexts creatively (Contribution 1; Kokotsaki et al., 2016; Kwon & Lee, 2025; Contribution 7). Moreover, traditional teacher-centered approaches are being challenged by the recognition that students must be active participants in their own learning (Dole et al., 2016; Contribution 2; Contribution 5; Strobel & van Barneveld, 2009). Project-Based Learning has emerged as a promising pedagogical approach positioned to meet this need by engaging students in authentic, real-world problems and meaningful projects over extended periods (Diana & Sukma, 2021; Contribution 5; Krajcik & Blumenfeld, 2006; M. Y. Lee & Robles, 2019; Markham et al., 2003; PBL Works, 2019; Contribution 8; Contribution 10).

2. Project-Based Learning

A Project-Based Learning (PBL) curriculum engages learners in meaningful problems that are important to them while advancing their creativity and problem-solving abilities (Kokotsaki et al., 2016). The PBL model is based on the assumption that most academic content is learned best in the context of projects (Blumenfeld et al., 1991).

PBL is an inquiry-based instructional approach that reflects a learner-centered environment and concentrates on learners’ application of disciplinary concepts, tools, experiences, and technologies to research the answers to questions and solve real-world problems (Condliffe et al., 2017; Larmer et al., 2015). PBL can aid in enhancing both the range of learners’ interests and their conceptual understanding of content. Teachers support ways for learners to construct their own understanding and orchestrate conversations in which learners explore complex connections and relationships among ideas.

General core principles and practices of PBL include the following (J. S. Lee & Galindo, 2021):

• Promoting a professional culture of trust, respect, and responsibility among the learners and the teacher
• Focusing on 21st-century skills and content standards
• Improving character education traits such as leadership, civic responsibility, and compassion
• Scaffolding activities that include student-centered instruction to increase relevance and rigor
• Connecting learning to other subject areas
• Infusing technology as a tool for communicating, collaborating, and learning
• Partnering with community institutions so that learners can build relationships with other local stakeholders

In this commentary, we explore how PBL serves as a critical approach for integrated STEM education. We synthesize insights from ten research papers in this Special Issue, focusing on its role in (1) fostering interdisciplinary learning; (2) supporting civic engagement; (3) promoting equity, identity, and inclusion; and (4) examining innovative pedagogical approaches. A discussion on future directions follows.

3. Interdisciplinary STEM Learning

Integrated STEM education emphasizes combining discrete subject areas in relevant contexts to deepen students’ understanding and awareness of connections across disciplines (Hall & Miro, 2016; Contribution 7). PBL provides a robust framework for this integration by engaging students in authentic problems that inherently require drawing upon knowledge and skills from multiple STEM fields (M. Y. Lee & Robles, 2019; Contribution 8; Contribution 10).

Several examples in this Special Issue illustrate how PBL facilitates this interdisciplinary STEM approach. The Challenges in the STEM Learning Framework integrates features of PBL, Design-Based Learning, and Entrepreneurial-Based Learning to center mathematics learning within innovative pitch competitions (Contribution 1). This approach explicitly aims to foreground the mathematics within interdisciplinary STEM activities by making visible and central the contribution of mathematics to addressing challenges involved with entrepreneurial solutions (Contribution 1; Contribution 7). Another innovative combination involves integrating PBL with flipped classrooms, which has demonstrated significant improvement in students’ computational thinking skills in mathematics, specifically decomposition, pattern recognition, and abstraction (Contribution 4).

Interdisciplinary PBL provides rich opportunities for students to integrate knowledge, collaborate across fields, and engage with real-world issues. In higher education, multidisciplinary Capstone Senior Design Projects in fields such as Electrical Engineering, Mechanical Engineering, and Computer Science require collaborative efforts across these domains (Contribution 6). Similarly, the STEM Oriented Alliance for Research project engages university students across Electrical Engineering, Communications, and Marketing majors to foster collaborative abilities crucial for navigating diverse professional fields (Contribution 9). In one study (Contribution 3), the authors described an undergraduate engineering course that successfully integrated engineering with social issues by using homelessness as the context for an engineering design project, connecting technical learning with public welfare and ethics. The authors of another study (Contribution 2) reported a case study involving university exchange students in education tasked with developing interdisciplinary STEM lessons combining mathematics and environmental science, leveraging place-based education to ground learning in local contexts. At the K-12 level, gardening-based learning exemplifies integrated PBL, naturally drawing connections across environmental studies, mathematics, science, and language arts (Contribution 8).

Despite these successes, challenges persist in ensuring rigorous and deep integration of disciplinary content within PBL frameworks. Teachers often struggle to design projects that effectively drive the learning of core disciplinary standards, particularly for mathematics (Contribution 7; Contribution 10), while balancing them with PBL elements (Contribution 10). In one of the included studies, pre-service teachers, for instance, varied in their ability to integrate mathematics as a core, not auxiliary, part of STEM PBL units (Contribution 7).

4. Civic Engagement

A hallmark of effective PBL in integrated STEM is its emphasis on authenticity, often achieved by grounding projects in real-world problems or contexts that allow for civic engagement and impact (Contribution 5; Contribution 7; Contribution 8). This approach prepares students to be active and responsible citizens capable of addressing societal challenges.

One powerful example is the engineering design project referenced above in which university students engaged with issues faced by people experiencing homelessness (Contribution 3). The aim of this project was to shift students’ views on homelessness by linking engineering skills to ethical and societal considerations. The researchers (Contribution 3) noted that a major goal of the project was to combat a “culture of disengagement” by relating learning directly to sociotechnical applications. Similarly, a group of researchers (Contribution 2) studied university exchange students focusing on localized environmental problems in their STEM lessons. The Design & Pitch framework also situates its challenges within real-world contexts that affect various stakeholders, addressing pressing issues such as pollution, food waste, and economic viability, empowering students with the autonomy to identify personally meaningful pursuits (Contribution 1). The Community Garden Project (Contribution 10) is a discipline-rich PBL, tasking students to serve as activists and urban farmers to address food insecurity in their community by designing a school garden and proposing its implementation to the administration.

Beyond disciplinary content, PBL in integrated STEM environments is a vital vehicle for developing essential 21st-century skills critical for civic participation and professional life (Bell, 2010; Rehman et al., 2023). Collaboration, critical thinking, problem-solving, and communication are inherently fostered through the PBL process (Contribution 7). The authors of a comparative analysis of multidisciplinary Capstone Senior Design Projects found that both industry-sponsored and faculty-sponsored projects aided in the development of professional skills; industry-sponsored projects led to higher performance in overall project execution and professional skills development such as punctuality and listening, while faculty-sponsored projects were particularly effective in nurturing teamwork and communication abilities (Contribution 6). The aim of the STEM Oriented Alliance for Research project (Contribution 9) was to develop collaborative abilities such as positive interdependence, accountability, proactive interaction, group processing, and social skills, directing students’ learning orientations towards future professional work. These examples demonstrate how PBL provides a structured environment for students to develop the essential 21st-century skills in interdisciplinary workforces and active civic engagement (Contribution 6; Contribution 9).

Furthermore, projects grounded in social issues cultivate social awareness, empathy, and a sense of responsibility. The homelessness project led to statistically significant shifts in students’ perceptions. Their views moved away from biases about personal choices or moral deficiencies, and toward more compassionate, empathetic perspectives. The project reinforced the idea that engineers have a duty to care for those experiencing homelessness. It also showed that PBL can counter a technocratic view of engineering by emphasizing its sociotechnical nature and the importance of compassion and empathy (Contribution 3).

5. Equity, Identity, and Inclusion

Culturally responsive approaches are central to achieving equity and inclusion. PBL holds significant potential for addressing long-standing issues of underrepresentation in multiple STEM fields, particularly for groups such as women and Hispanic communities (Contribution 1; Contribution 8). By connecting learning to students’ lives, cultures, and communities, PBL can foster STEM identity development and narrow achievement gaps for underrepresented students (Cross et al., 2012; Contribution 8; Contribution 10).

A group of researchers (Contribution 8) provide a compelling example of this point in the Family Project-Based Learning, a garden-based STEM program for Latina girls and their parents centered around planning, growing, and harvesting food. The authors describe this program as actively leveraging community cultural wealth, including aspirational, linguistic, familial, social, navigational, and resistance capital, to support STEM identity development through authentic, hands-on activities. The provision of English/Spanish bilingual instruction was critical, validating and building upon families’ linguistic capital. This approach directly addresses the lack of access and role models that contribute to the underrepresentation of Latinas in STEM, promoting the idea that diverse perspectives and talents are essential for innovation (Contribution 8).

Another group of researchers (Contribution 1) report on how the framework also contributes to inclusion by featuring diverse STEM professionals as “challenge champions” who introduce projects, showcasing a range of careers and backgrounds. These role models aid students in seeing their own identities reflected in STEM and entrepreneurship, empowering them to draw on their unique experiences and STEM knowledge to invent solutions. Similarly, the homelessness project in engineering education (Contribution 3) advocates for a more inclusive, justice-oriented education that addresses systemic inequities and encourages students to reflect on privilege and disadvantage, further supporting an equity-focused approach (Contribution 3).

Furthermore, integrating social justice and global awareness into PBL STEM units aids in preparing pre-service teachers to address issues such as environmental, racial, gender, disability, and economic inequities with their future students (Contribution 7). PBL, in this context, becomes a tool for future educators to make a tangible difference in the lives of their students, though challenges in integrating potentially controversial topics may emerge (Contribution 7). The collaborative nature of PBL supports inclusion, as seen in a case study wherein culturally diverse exchange students used technology to enhance communication and understanding while developing curricula together (Contribution 2). The STEM Oriented Alliance for Research project showed that despite initial challenges, interdisciplinary teamwork across various majors fosters understanding, mutual appreciation, and a growth mindset (Contribution 9).

6. Pedagogical Innovations and Frameworks

PBL is defined by core elements such as a challenging problem, sustained inquiry, authenticity, student voice and choice, reflection, and a public product, shifting the focus from teacher-directed instruction to students’ active construction of knowledge (Contribution 5; Contribution 7; Contribution 8; Contribution 10). The papers included in this Special Issue highlight various innovative adaptations and frameworks aimed at enhancing the effectiveness of PBL in integrated STEM contexts.

One such innovation is the framework involving Launch, Design, and Pitch phases (Contribution 1), which synthesizes PBL, Design-Based Learning, and Entrepreneurial-Based Learning into an integrated model for mathematics education, drawing on key features from each, such as sustained inquiry from PBL, iterative design from Design-Based Learning, and persuasive pitching from Entrepreneurial-Based Learning. This approach emphasizes authenticity and entrepreneurial viability through technical briefs and public critiques like expert check-ins and the final pitch (Contribution 1). Another integrated model combines PBL with flipped classrooms, wherein students engage in independent learning outside of class using resources such as videos and then apply and discuss their understanding in interactive face-to-face sessions, significantly improving their computational thinking skills (Contribution 4).

Innovative adaptations of interdisciplinary STEM PBL expand its potential by integrating new pedagogical approaches, fostering student agency, family engagement, and professional collaboration. Students acted as “lesson architects” to develop an interdisciplinary STEM curriculum through a unique adaptation integrating PBL with place-based education, lesson study, and the “students as partners” pedagogy (Contribution 2). This approach positions students as decision-makers and co-creators, embedding iterative processes through lesson study (Contribution 2). The Family Project-Based Learning in a gardening context (Contribution 8) offers a model specifically designed for engaging families from underrepresented communities, in which they practice emphasizing discussion before action and exploration before explanation within a hands-on project. The STEM Oriented Alliance for Research project (Contribution 9) represents an industry-modeled interdisciplinary PBL approach for university students, structured with multiple checkpoints and feedback loops to emulate professional settings and foster collaborative abilities.

However, challenges to implementing these innovations persist. Teachers not only struggle to design projects that effectively integrate and drive the learning of core disciplinary standards but also find it difficult to balance the elements of PBL with specific content and practice pathways (Contribution 10). In particular, pre-service teachers are likely to have difficulty consistently integrating key PBL elements such as sustained inquiry, student voice and choice, reflection, and public product or ensuring that mathematics is genuinely integral to the project (Contribution 7). Challenges also include teachers’ need for strong facilitation skills and adequate resources (Contribution 4), in addition to mentorship and varying expectations in industry-sponsored projects (Contribution 6). Furthermore, current assessment instruments may be constrained by limitations in accurately capturing the nuanced shifts in students’ perceptions that occur in PBL environments (Contribution 3).

To address these challenges, frameworks and conceptual tools are currently being developed. To support teachers in managing the complex goals of STEM PBL design, a group of researchers (Contribution 10) propose the Project Planning Pyramid. This conceptual tool aids teachers in designing ‘discipline-rich’ STEM projects by explicitly integrating key elements. It combines the PBL framework with a Content Storyline—a coherent sequence of content ideas—and a Practice Pathway, which provides sequenced opportunities to build disciplinary practices. Embedding formative assessment processes within projects, as in the STEM Oriented Alliance for Research project, provides opportunities for iterative application of criteria, feedback, and self-reflection, aiding students in understanding expectations and improving their work (Contribution 9). Comparing different student-centered methods, such as PBL and Problem-Based Learning, highlights the unique characteristics of PBL. These include its broader scope, emphasis on sustained inquiry, and the creation of tangible products. PBL often encompasses other methods within its wider project framework (Contribution 5).

7. Future Directions

Building upon these four sections, the trajectory for future exploration of PBL in integrated STEM education must focus on methodological rigor and nuanced assessment. There is an urgent need for researchers to conduct larger-scale, longitudinal studies across diverse contexts to capture the multifaceted learning and perception shifts fostered by interdisciplinary PBL. Such studies are crucial for understanding the sustained development and transferability of skills, such as computational thinking, to real-world and professional settings (Contribution 4; Contribution 8). Utilizing robust mixed-methods approaches is important, allowing researchers to integrate quantitative data for generalizability and qualitative insights for a more nuanced understanding, as demonstrated or recommended in several studies (Contribution 3; Contribution 4; Contribution 8). This scope includes employing strategies like theoretical sampling and thematic analysis in qualitative phases (Contribution 2; Contribution 4; Contribution 8). In this regard, further work is needed to refine assessment instruments that are sensitive to the unique learning outcomes and attitude shifts in integrated STEM PBL, which potentially includes adapting or revalidating existing instruments for specific contexts (Contribution 3). Exploring innovative data collection and analysis methods, such as visual analysis or detailed case studies, will aid in capturing the nuances of student engagement and learning processes.

The authors of future studies should also include in-depth investigation of the long-term impacts of integrated PBL on student outcomes, including how participation influences mindsets, collaborative abilities, and career trajectories in multiple STEM fields. Clarifying PBL’s long-term impacts requires understanding how integrated models and PBL elements support learning and identity formation, such as exploring the effectiveness of combining PBL with flipped classrooms for specific skill enhancement (Contribution 4), integrating Design-Based Learning and Entrepreneurial-Based Learning to authentically center disciplines such as mathematics (Contribution 1), or leveraging place-based education and “students as partners” pedagogies for engagement with complex issues (Contribution 2). Further study of various models, such as faculty-sponsored versus industry-sponsored projects, can highlight their unique benefits and challenges in developing practical skills and teamwork (Contribution 6).

Lastly, supporting educators in effectively designing and implementing discipline-rich PBL in integrated STEM remains paramount to improve the long-term impacts of PBL. Thus, further research is needed to understand how various conceptual frameworks or models support teachers’ pedagogical design capacity for creating projects that meaningfully integrate content, disciplinary practices, and PBL elements. In addition, providing sustained professional learning experiences built on such frameworks or models is crucial for aiding teachers in balancing the demands of integrated STEM PBL. Most urgent is the targeted mathematics support that is often marginalized in integrated contexts (English, 2016). By pursuing these interconnected avenues, the field can continue to harness PBL’s transformative power to prepare students for a complex and interdisciplinary future.