Inclusive education is a central principle of education policy and reform across Europe and internationally, underpinned by commitments to equity, participation, and the rights of learners. International frameworks such as the UNESCO Salamanca Statement (1994), the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD; United Nations, 2006), and UNESCO’s Education 2030 agenda position inclusion as both a rights-based imperative and an indicator of educational quality. Across many education systems, these commitments have driven sustained efforts to increase the participation of students with disability in mainstream settings, alongside growing expectations that inclusive education should contribute to improved academic, social, and wellbeing outcomes for all learners.

Previous research indicates that inclusive education is associated with positive outcomes for both students with and without disability (Dalgaard et al., 2022; Holzer & Moser Opitz, 2025; Szumski et al., 2017). Less frequently examined in the literature, however, is a fundamental issue underpinning this evidence base: what is actually being evaluated when the effectiveness of inclusive education is assessed. Much of the existing research infers effectiveness primarily through placement-based comparisons, typically comparing outcomes for students placed in mainstream versus specialist or segregated settings. While such analyses are important for understanding system-level patterns and policy effects, they offer limited insight into the pedagogical and instructional practices that may be responsible for observed outcomes. 

Scholars have increasingly drawn attention to this gap in the evidence base underpininning inclusive education practices. Koutsouris et al. (2023) argue that inclusive pedagogies are often fragmented and under-theorised, particularly in secondary school contexts, while Norwich (2013) highlights the dominance of “thin” empirical accounts. Similarly, systematic reviews of inclusive education approaches such as Universal Design for Learning (UDL) and co-teaching demonstrate substantial variation in how practices are defined, operationalised, and reported, limiting the interpretability and transferability of outcome findings (Ok et al., 2017; Vembye et al., 2024; Zhang et al., 2024).

In response to these concerns, the aim of this systematic review is to synthesise and assess empirical evidence on the effectiveness of inclusive practices in school settings, with a focus on their reported impact on student outcomes.This review examines how inclusive practices are defined, operationalised, supported, and evaluated across studies, and how these practices are linked to learner outcomes.Although much of the empirical literature on inclusive practices continues to focus on students with disability, this review adopts a broader conceptualisation of inclusion concerned with educational practices that support participation, learning, and engagement for all students. Disability status was therefore not used as an inclusion or exclusion criterion. Instead, studies were selected based on their explicit engagement with inclusive practice and their reporting of student outcomes, allowing the review to examine how inclusion is enacted and evaluated across diverse learner groups and school contexts.

Drawing on a systematic review and appraisal of empirical studies published since 2015, the review synthesises research conducted in primary and secondary school contexts that explicitly reports learner-related outcomes associated with inclusive practices. By identifying patterns, gaps, and limitations in the existing evidence base, this review contributes to international debates about how inclusive education can be more effectively conceptualised, researched, and enacted, and how evidence on inclusive practices can better inform educational policy, professional learning for educators, and school improvement across diverse educational contexts.

This study adopts a systematic literature review methodology (Gough et al., 2012) following PRISMA guidelines (Page et al., 2021). A comprehensive search strategy was developed to identify empirical studies examining inclusive practice and its impact on students in school contexts. Searches were conducted across five major international databases in educational research: ProQuest (Central), Scopus, ERIC (EBSCO), PsycInfo, and Web of Science. A structured search string was developed by combining terms related to inclusion and teaching practice (e.g., “inclus educat*” OR “inclus* practice*” OR “inclus* pedagog*” OR “inclus* teach*”) with terms relating to impact on learners (e.g., “student” OR “learner”; “outcome*” OR “impact*” OR “result*”). Searches were limited to peer-reviewed journal articles published in English since 2015. The search yielded 989 records. All records were imported into Rayyan and duplicates were removed. Screening proceeded in two phases using predefined inclusion and exclusion criteria. In Phase 1, titles and abstracts were independently screened by at least two authors. Studies were included if they reported original empirical research conducted in primary or secondary contexts and engaged explicitly with inclusive practice, with a stated focus on impact on learners. Studies were excluded if they were conducted exclusively in higher education, focused solely on policy analysis or conceptualisations, or on teachers’ perceptions or beliefs without reference to learner impact, or did not report any learner-related outcomes. Where eligibility could not be determined from the abstract alone, full texts were retrieved for further assessment. In Phase 2, 134 full-text articles were reviewed in detail by at least two authors to confirm eligibility; discrepancies were resolved through a third researcher adjudicating and discussion where required. Following full-text screening, 24 studies met the final inclusion criteria. Data extraction and analysis then proceeded using a purpose-built coding matrix capturing publication details, research context, methodological approach, targeted learner groups (e.g., EAL learners; students with disabilities), reported findings and implications, and, critically, how inclusive practice was defined, operationalised, supported, and evaluated (including impact on learners and/or teachers) and space for additional notes. Following data extraction, the review employed thematic synthesis to identify recurring patterns, dominant framings, and under-theorised dimensions of inclusive practice. To enhance transparency and rigour, study quality was appraised using the Mixed Methods Appraisal Tool (Hong et al., 2018). Analytic decisions were documented throughout, and the synthesis prioritised conceptual coherence and variation across studies rather than frequency counts alone.

This review aims to provide a nuanced and evidence-informed account of how inclusive practice is enacted and evaluated in contemporary school-based research. Findings indicate that inclusive practice is operationalised through a relatively narrow set of pedagogical approaches, most prominently Universal Design for Learning (UDL), differentiated instruction, peer-assisted learning, co-teaching, technology-assisted practices, and culturally responsive pedagogy. UDL emerged as the most frequently examined framework, particularly in literacy-focused interventions and technology-supported designs, while co-teaching and peer-assisted approaches appear less consistently theorised and more context-dependent. The review also reveals that inclusive practices are predominantly implemented at the classroom level, often as short-term interventions, with limited attention to fidelity, sustainability, or whole-school alignment. Contextual factors such as leadership, school culture, and policy environments are rarely examined systematically. This contributes to a tendency to individualise inclusion as a matter of teacher practice rather than a relational and institutional process. In terms of impact, the synthesis shows that student outcomes are most commonly assessed within three domains: academic achievement (particularly reading and subject-specific attainment), engagement, and social-emotional outcomes. Academic outcomes are typically measured using standardised or curriculum-based assessments, while engagement and social-emotional outcomes rely more heavily on self-report instruments, observational data, or qualitative accounts. While several studies report positive associations between inclusive practices, especially UDL-informed approaches, and student learning or engagement, evidence remains uneven and fragmented. Links between specific practices and outcomes are often implied rather than robustly established, and negative or null findings are under-theorised. This systematic review highlights a persistent gap between conceptualisations of inclusive education and the way inclusive practice is empirically examined. By foregrounding patterns of practice, measurement, and impact, the review contributes a more critical and nuanced understanding of what counts as inclusive practice and how its effectiveness is currently examined in the literature.

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