Inclusion in ECEC is, above all, a fundamental right for all children. Both the United Nations’ Convention on the Rights of the Child (CRC) and the Convention on the Rights of Persons with Disabilities (CRPD) affirm the equal right of children with and without disabilities to participate in education and in other areas of life, including cultural activities, leisure, and sports (United Nations, 1989, 2006). Within the context of ECEC, inclusion has been defined as “children with delays and disabilities being integrated into the classroom and school communities, having equitable and active participation in social activities with typically developing peers, and having reciprocal and positive relationships with peers and adults” (McGuire and Meadan, 2022, p. 63). Research suggests that inclusive settings—as opposed to segregated settings—can benefit both children with and without disabilities, particularly in areas such as language and communication development (Blackmore et al., 2016; Rafferty et al., 2003), social-behavioral outcomes (Blackmore et al., 2016; Buysse and Bailey, 1993), social acceptance, and the development of peer-relations and friendships (Guralnick, 1999; Odom et al., 2012). However, some studies indicated that children with disabilities are at greater risk of social isolation and rejection compared to their peers without disabilities (Guralnick, 1999; Lloyd-Esenkaya et al., 2020). They often have smaller social networks (Chen et al., 2019) and show lower levels of participation (Benjamin et al., 2017; Slavković et al., 2021). Preliminary research suggests that children’s participation may vary depending on the activity or social context (Golubović et al., 2022; Luttropp and Granlund, 2010). However, participation in ECEC remains less well understood than in school settings (Benjamin et al., 2017), underscoring the importance of identifying both facilitators and barriers to the participation of young children with disabilities (Odom et al., 2012).

The World Health Organization’s International Classification of Functioning, Disability and Health (ICF) is based on a biopsychosocial model and serves as a globally recognized framework for describing an individual’s functioning and disability. Within this model, activities and participation are linked to an individual’s health condition and body functions and structures, while also being influenced by personal and environmental (contextual) factors. Although activities and participation are described as distinct constructs, they are presented within a single domain in the ICF. The term activity refers to the “execution of a task or action by an individual” (World Health Organization, 2001, p. 10), whereas participation is defined as “involvement in a life situation” (World Health Organization, 2001, p. 10). The ICF does not offer a clear method for differentiating between these two constructs, leading to varied operationalizations in empirical research and complicating comparisons across studies (Coster and Khetani, 2008; Maxwell et al., 2018; Piškur et al., 2014). In an attempt to further differentiate between activities and participation, Whiteneck and Dijkers (2009) stated that activities “can be done alone while participation gains its societal perspective by performance with or for others” (p. S24). Similarly, Eyssen et al. (2011) argued that participation inherently involves a social context, requiring interaction with other people. This perspective aligns with other conceptualizations that define participation as “taking part” (Law, 2002, p. 641) or “being included” (Rainey et al., 2014, p. 2794). Rainey et al. (2014) further noted that full participation encompasses different activities.

To provide greater conceptual clarity, Imms et al. (2016, 2017) developed the family of participation-related constructs (fPRC), which differentiates between two core components of participation: attendance—the act of “being there,” which is considered a necessary dimension but not sufficient prerequisite for involvement (Ullenhag et al., 2024). Attendance may be assessed through indicators such as frequency, range, or diversity of activities, whereas involvement is defined as “the experience of participation while attending” (Imms et al., 2017, p. 18). Involvement may encompass aspects such as engagement, motivation, and level of affect. In addition, activity competence, sense of self, and preferences are identified as related yet distinct constructs that can both influence and be influenced by participation (Imms et al., 2017). Special attention is paid to the element of engagement, which is widely regarded as a crucial outcome supporting children’s learning and development in early childhood and is often even used interchangeably with involvement (Adolfsson et al., 2018; Ritoša et al., 2023).

In recent years, a variety of measures have been developed to assess the participation of children with disabilities (for an overview, see Adair et al., 2018; Chien et al., 2014; Phillips et al., 2013; Rainey et al., 2014). These measures are based on different frameworks and employ various constructs to operationalize participation. If participation is not clearly defined in the study design, discrepancies may arise between the selected assessment tools and the theoretical frameworks they are intended to reflect, which can ultimately affect the reported results on children’s participation (Coster and Khetani, 2008; Imms et al., 2016).

Taken together, although a considerable number of studies address the participation of children with disabilities, it remains largely unclear what is actually being studied when the term participation is used. While attendance and physical presence are necessary components, they do not ensure active involvement in meaningful learning experiences. Therefore, it is essential to examine how participation—and its related subconstructs, such as involvement and engagement—is defined across studies, specifically identifying the theoretical frameworks and conceptual models underpinning the research. Equally important is understanding how these constructs are operationalized, what variables and which tools or instruments are used to assess children’s participation. From a research perspective, such a review could enhance the comparability and coherence of future studies focusing on participation in ECEC settings. From a practical and policy-oriented standpoint, there is a need to synthesize findings related to the participation of children with disabilities—particularly with regard to the types of activities, social contexts, and other factors that may facilitate or hinder their participation. Accordingly, we addressed the following research questions:

The search for eligible articles was carried out in four electronic databases—ERIC, Education Source, PsycINFO, and Web of Science—in February 2023. Search terms were derived from the PICo components and applied to titles, abstracts, and keywords as follows: (participation OR attendance OR involvement OR engagement) AND (early childhood education OR preschool* OR kindergarten*) AND (disab* OR impair* OR developmental* delay* OR special need* OR special education OR inclusi*). This search string was piloted prior to the full search and found to be comprehensive, as the addition of further search terms did not yield additional relevant results. In addition to the database search, reference lists of included articles were screened and the table of contents of relevant scientific journals published between 2001 and September 2023 were hand-searched for further eligible studies. The following journals were searched: Early Childhood Research Quarterly; Early Child Development and Care; European Early Childhood Education Research Journal; European Journal of Special Needs Education; Frontiers in Education; International Journal of Disability, Development and Education; International Journal of Inclusive Education; Topics in Early Childhood Special Education. In April 2025, the database search and journal hand-searches were updated to capture studies published since the initial search. The same search terms, limits, and selection criteria were applied in this update.

The search was limited to articles published from 2001 onward, as the publication of the ICF in that year significantly contributed to the conceptualization of participation in both research and practice (Adair et al., 2018). Only empirical studies published in English and in a peer-reviewed scientific journal were eligible for inclusion to ensure methodological rigor. Consequently, the publication date, language, and peer-review-status were applied as search limits in all four databases. Studies were included if participation (or the related subconstructs of involvement or engagement) was the primary outcome and the sample included children with disabilities between the ages of 3 and 6 years attending inclusive ECEC settings. Studies including children outside this age range were eligible only if the majority of participants fell within the specified age range or if results were reported separately by age group. The target population was not limited to specific diagnoses or types of disability. Studies examining participation in settings other than inclusive ECEC or in segregated ECEC programs were excluded. Some studies that initially appeared relevant—such as Benjamin et al. (2017)—were excluded because they did not provide information on whether the children attended inclusive ECEC settings. Studies that included elements of participation or related constructs, but focused primarily on other outcomes—such as specific skills or behaviors (e.g., social attention skills, play behavior)—were excluded if they did not report explicit results on children’s overall participation. This criterion particularly applied to intervention or evaluation studies, which therefore were excluded from this review (Webster and Carter, 2007). Additionally, studies reporting only attendance in ECEC were excluded, as involvement in activities is considered a vital factor for participation (Imms et al., 2017). We also excluded studies that measured the engagement solely with toys, materials, or other inanimate objects without considering the social context of participation (Eyssen et al., 2011; Whiteneck and Dijkers, 2009). Following Rainey et al. (2014), studies examining participation in only one activity were excluded, except when the activity was characterized as free play, which typically allows children to choose and switch between different activities and interact with peers and/or adults (Kemp et al., 2013). Studies assessing the validity of measurement instruments were generally eligible for inclusion. However, those focusing exclusively on psychometric properties without providing detailed participation-related results were excluded (e.g., Khetani et al., 2015; Kishida et al., 2008). Table 1 summarizes the key inclusion and exclusion criteria.

Search results were exported to EPPI-Reviewer (Thomas et al., 2019), a reference management software for systematic reviews, and duplicates were removed. The first author screened all titles and abstracts according to the predefined inclusion criteria. Additionally, 5% of the records were independently screened by the second author. Any disagreements were resolved through discussion. Articles for which a decision could not be reached based on title and abstract were assessed via full-text screening. One third (33%) of all full-texts were independently reviewed by the second author. No automation tools were used during the study selection process.

Figure 1 presents the study selection process, including the number of eligible studies and the reasons for exclusion. The initial database search yielded 4,474 records, of which 1,311 were removed as duplicates. Of the remaining 3,163 records, 3,061 were excluded following the screening of titles and abstracts. The full texts of the remaining 102 articles were retrieved and assessed for eligibility, resulting in the exclusion of 81 studies. The percentual agreement between the two authors was 96% at the title and abstract level and 97% at the full-text level. Any discrepancies were resolved through discussion until consensus was reached. In addition to the remaining 21 studies, four studies were identified through hand-searching reference lists and scientific journals, leading to 25 studies included. During the search update, 827 records were screened on title and abstract, of which 13 were included in the full-text screening. Three additional studies that met the inclusion criteria were identified. In total, 28 studies were included in this review.

Data were extracted from the included studies using a piloted, study-specific data extraction form developed for this review (available upon request from first author). Fifty percent of the extracted data were double-checked by the second author. Extracted information, either directly quoted or paraphrased from the respective articles, included: study aims and objectives, research question(s), country, methodology (quantitative, qualitative, or mixed-methods; cross-sectional or longitudinal), data collection methods (e.g., observation, interviews), sample characteristics (sample size, age, disability/diagnosis), educational setting(s), definition of participation or related constructs, operationalization and measurement/coding tools, activities or social contexts, and key findings.

The methodological and reporting quality of all included studies was assessed using the Quality Assessment with Diverse Studies (QuADS) tool (Harrison et al., 2021). This tool was chosen because the review included heterogeneous evidence bases comprising both qualitative, quantitative, and mixed-methods studies. QuADS provides a single framework for evaluating conceptual clarity, methodological rigor, and relevance across diverse designs, thereby ensuring consistency in appraisal. Thirteen criteria were rated on a 4-point scale from 0 to 3, covering aspects such as: theoretical or conceptual underpinning; clarity of research aims; description of research setting, target population, recruitment, and data collection procedures; appropriateness of study design, sampling, data collection tools, and analytic methods; stakeholder involvement in research design or conduct; and critical discussion of strengths and limitations. A score of 0 was assigned if no information was provided on a criterion, while a score of 3 indicated explicit, detailed explanations and appropriate design to address the research aims. This quality appraisal did not influence study inclusion or exclusion, but provided important context for interpreting study results. To ensure consistency, the authors first independently scored a subset of studies and discussed point allocation afterwards to develop a shared understanding of the criteria. Subsequently, the first author conducted the quality assessment for the remaining studies, with any uncertainties resolved through discussion with the second author.

The data were analyzed using a narrative synthesis approach (Ryan, 2013). Initially, general information from all included studies was summarized to provide an overview of study characteristics. Methodologies and data collection approaches were categorized and sample characteristics were compared. Studies were grouped based on whether they included only children with disabilities or compared children with and without disabilities. Next, the studies’ definitions of participation were examined, noting whether they provided explicit, stand-alone definitions of participation or related constructs and referenced specific theoretical frameworks. The operationalization and measurement of participation were then analyzed, categorizing the measurement tools applied and the variables used. Also, the activities and social contexts studied were compared. Finally, the major findings regarding the participation of children with disabilities in inclusive ECEC were synthesized across studies, focusing on similarities and differences in participation levels compared to peers without disabilities, interaction patterns, and factors influencing participation.

Twelve of the 28 studies (43%) included only children with disabilities (Barbas et al., 2006; Casey et al., 2012; Despois and André, 2024; Hu et al., 2016; Kemp et al., 2013; Kishida and Kemp, 2006, 2009; Odom et al., 2006; Olsen et al., 2019; Pinto et al., 2019; Syrjämäki et al., 2023; Tsao et al., 2008), while the remaining 16 studies (57%) compared children with and without disabilities. Across all studies, the sample sizes ranged from a single participant to 1,623, with the number of children with disabilities ranging from one to 145. The participating children had a range of disabilities, with the most commonly reported diagnoses being a (global) developmental disability or delay, autism spectrum disorder (ASD), (speech and/or) language disorder, Down syndrome, intellectual disability, and physical or sensory impairment. However, nine studies did not specify the diagnosis or type of disability, but rather referred to participants more generally as having some kind of special educational needs or a documented disability (Åström and Almqvist, 2022; Casey et al., 2012; Coelho et al., 2019a; Golubović et al., 2022; Harper and McCluskey, 2002; Kishida and Kemp, 2006; Kuutti et al., 2022; Nesbitt and Farran, 2022; Tsao et al., 2008). Eleven studies included only children with a specific type of disability (e.g., ASD, Kishida and Kemp, 2009; Syrjämäki et al., 2023; Despois and André, 2024; Down syndrome, Hamilton, 2005). Five studies also included children they labeled as “at risk” or “informally identified” as having a disability (Åström and Almqvist, 2022; Coelho et al., 2019a; Coelho et al., 2019b; Coelho et al., 2023; Coelho and Pinto, 2018). The reporting of children’s age varied across studies. Some reported age in months, others in years, while several provided only an age range without mean age or standard deviation. This inconsistency in reporting is reflected in Table 2 and prevents the calculation of a precise overall mean age. Still, the age range across studies could be estimated to span from 45 to 70 months.

Out of all studies, five (18%) defined participation as “involvement in a life situation” (World Health Organization, 2001, p. 10), following the ICF (Åström and Almqvist, 2022; Coelho et al., 2019a; Coelho and Pinto, 2018; Leung et al., 2011; Pinto et al., 2019). Although Castro and Pinto (2015) did not provide a stand-alone definition of participation, they referred to the ICF as a theoretical foundation. Similarly, Coelho et al. (2019b) did not define participation explicitly, but provided a detailed definition of the related construct of engagement. Coelho and Pinto (2018) emphasized that participation is a multidimensional and “health-related concept depicting transitional processes between the person and the environment” (p. 2). Three studies distinguished between attendance and involvement as the two components of participation, in line with the fPRC by Imms et al. (2017) (Åström and Almqvist, 2022; Coelho and Pinto, 2018; Pinto et al., 2019). Another study described participation as “to be part of” (Folha and Barba, 2022, p. 4) and elaborated it as “sharing, engaging, being active or experience something” (Folha and Barba, 2022, p. 7), highlighting feelings of acceptance and belonging as central to the concept. Finally, three studies used the term ‘social participation’, although only one of them provided a stand-alone definition (Harper and McCluskey, 2002; Odom et al., 2006; Tsao et al., 2008).

Nineteen of the 28 studies (68%) did not analyze participation as the main outcome. Instead, they focused on related constructs such as involvement or engagement—either independently or in conjunction with participation (see Table 3). Involvement was described as one dimension of participation, characterized as a state in which children participate in an activity with motivation, concentration, interest, and persistence. This state is marked by openness to cognitive or sensorial stimuli. Involvement was also linked to children’s well-being (Golubović et al., 2022; Kuutti et al., 2022; Syrjämäki et al., 2023) and was noted to include elements of engagement (Åström and Almqvist, 2022). Fifteen studies (54%) offered a definition of engagement, with many of them referring to McWilliam and Bailey (1992, 1995). For example, Casey et al. (2012) defined engagement as “the amount of time children spend interacting with the environment (adults, peers, and materials) in a developmentally and contextually appropriate manner (McWilliam and Bailey, 1992)” (p. 122). Similarly, Coelho et al. (2019b) defined engagement as “children’s active participation in classroom tasks, activities, or routines” (p. 107). Fasano et al. (2023) used the term ‘classroom engagement’, defining it as “the ability to successfully participate in classroom tasks and with social partners” (p. 1587). Overall, many studies conceptualized involvement and engagement as indicators of high-quality inclusive ECEC and as critical outcomes for promoting children’s social and communication skills, broader participation, and future academic success (e.g., Coelho et al., 2023; Despois and André, 2024; Syrjämäki et al., 2023).

However, nine studies (32%) did not provide an explicit, detailed stand-alone definition of participation or of the related constructs of involvement or engagement (see Table 3). Instead, some referred to participation in a broader context, emphasizing its relevance for fostering inclusive environments (e.g., Barbas et al., 2006; Luttropp and Granlund, 2010; Olsen et al., 2019). In many cases, the conceptual relationships among participation, involvement, and engagement remained unclear. This was particularly evident when studies used the terms to define one another, as seen in Coelho et al. (2019b) or Fasano et al. (2023) when defining engagement (see above). Involvement was often characterized as a subconstruct of participation, consistent with the fPRC proposed by Imms et al. (2017). Other studies framed engagement as an important dimension of participation (Åström and Almqvist, 2022; Coelho et al., 2019a; Kuutti et al., 2022; Pinto et al., 2019). Golubović et al. (2022) explicitly differentiated the two constructs, defining involvement as “an internal state of interest towards an activity itself” and engagement as “the specific behavior, emotions, and thoughts” (p. 1). Nevertheless, eight studies (28%) used the terms involvement and engagement interchangeably (Åström and Almqvist, 2022; Coelho et al., 2019a; Coelho et al., 2019b; Coelho et al., 2023; Coelho and Pinto, 2018; Luttropp and Granlund, 2010; Nesbitt and Farran, 2022; Pinto et al., 2019). For example, Coelho and Pinto (2018) stated that the core dimension of engagement is equivalent to the concept of involvement. Taken together, the studies included in this review reflect a broadly shared understanding, but lack a consistent and clearly delineated distinction between involvement and engagement.

The Supplementary Table 1 provides all definitions of participation, involvement, and engagement identified in the included studies. For a concise summary, Table 3 presents an overview of which constructs served as the main outcome in each study, whether a stand-alone definition was offered, and which theoretical framework—such as the ICF or fPRC—was referenced.

Detailed information on how participation, involvement, and engagement were operationalized across studies is also presented in Supplementary Table S1. Based on the extracted data, six categories of variables were derived to facilitate comparison (see Table 3): (1) levels or types of involvement/engagement, (2) participation in different activities, (3) social relationships/interactions, (4) children’s behavior, (5) teacher’s behavior, and (6) other indicators (e.g., proximity, independence, target of attention). These categories reflect the range of constructs and measures used to assess participation in inclusive ECEC settings. Below, we summarize the key findings by category, highlighting the diversity of approaches to measure participation.

The majority of studies (n = 20, 71%) operationalized participation through levels or types of involvement or engagement, either as the main outcome or as one of several outcomes. Given the frequent lack of distinction between these two constructs, we grouped them into one category. This synonymous use of terminology was also reflected in the measurement tools used: For instance, seven studies applied the Child Observation in Preschool (COP; Farran, 2014; Åström and Almqvist, 2022; Coelho et al., 2019a; Coelho et al., 2019b; Coelho et al., 2023; Coelho and Pinto, 2018; Luttropp and Granlund, 2010; Nesbitt and Farran, 2022). Although one of COP’s scales was originally designed to measure involvement, it was frequently used to assess engagement, with some studies using the two terms interchangeably. Similarly, the Individual Child Engagement Record (ICER; Kishida and Kemp, 2006) or its revised version ICER-R (Kishida et al., 2008), respectively, was used in five studies (Despois and André, 2024; Hu et al., 2016; Kemp et al., 2013; Kishida and Kemp, 2006, 2009). This observational tool categorizes engagement into four types: active engagement, passive engagement, active nonengagement, and passive nonengagement. Two studies (Kuutti et al., 2022; Syrjämäki et al., 2023) used an adaptation of the Leuven Involvement Scale for Young Children (LIS-YC; Laevers, 1994), while Fasano et al. (2023) used the Individualized Classroom Assessment Scoring System (inCLASS; Downer et al., 2010) to assess four different domains of engagement (i.e., peer interaction, teacher interaction, task orientation, negative engagement). In another study, Hamilton (2005) conceptualized children’s engagement through their interactions with peers. These examples illustrate the considerable variation in how involvement and engagement were operationalized across studies.

Fourteen studies (50%) specifically analyzed how children participate in different activities (see Table 3), each with distinct focal points and criteria—such as comparing the participation between children with and without disabilities (Pinto et al., 2019) or observing children’s participation in different kinds of play situations (Åström and Almqvist, 2022). Walker and Berthelsen (2008) adapted Parten’s (1932) categories to rate the degree of social participation, while Leung et al. (2011) used a 6-point scale from the School Function Assessment (SFA; Hwang, 2008) to rate children’s participation across various activities. In contrast, Folha and Barba (2022) distinguished between different forms of participation based on characteristics such as social interaction, interest, initiative, and motivation.

The analysis of variables related to social relationships or interactions with peers and/or adults played a vital role in many studies (n = 19, 76%; see Table 3). For example, studies using the ICER-R coded for the occurrence of interactions and interaction partners (e.g., Kemp et al., 2013; Kishida and Kemp, 2009). Coelho and Pinto (2018), as well as Luttropp and Granlund (2010), used the COP to observe and analyze the interaction states of individual children with disabilities in inclusive ECEC (e.g., onlooker, social play; see Supplementary Table S1). In Fasano et al. (2023), peer and teacher interactions were evaluated as separate domains of children’s engagement.

Eight studies incorporated additional variables regarding children’s behavior (n = 3, 11%) and/or teacher’s behavior (n = 5, 18%) to capture elements of participation or relevant contextual factors (e.g., physical prompts; Kishida and Kemp, 2006). Further details are available in Supplementary Table S1. Other indicators used to assess participation (n = 7, 25%) included children’s proximity to peers and/or adults (e.g., Åström and Almqvist, 2022), their level of independence or need for support (Golubović et al., 2022), and their target of attention (Kuutti et al., 2022; Syrjämäki et al., 2023).

While most of the studies (75%) relied on a single method for data collection, seven studies (25%) applied additional methods. Overall, 21 studies (75%) used live observations, eight (28%) used questionnaires, and five (18%) assessed participation via video analysis (see Table 2). Among the observation-based studies, 14 (66%) did not use an additional approach. However, one study also included interviews with teachers (Barbas et al., 2006), Olsen et al. (2019) combined live observations with video analysis, and five other studies (24%) supplemented observations with questionnaires completed by ECEC professionals (Coelho et al., 2023; Coelho and Pinto, 2018; Luttropp and Granlund, 2010; Odom et al., 2006; Pinto et al., 2019). In total, 12 standardized measurement tools were identified, out of which eight were used for observations or video analysis, and four were questionnaires (an overview is available upon request from the first author). Among the studies using live and video observation (n = 25), 10 (40%) were based on a momentary time sampling approach and nine (36%) used a systematic behavior sampling method—referred to as the “snapshot” procedure (Coelho et al., 2019b; Farran, 2014). One study used event sampling (Harper and McCluskey, 2002) and two others (Fasano et al., 2023; Pinto et al., 2019) applied rating-based observations. The most frequently used tools were the COP (Farran, 2014) and the ICER-R (Kishida et al., 2008). Two other observation tools were used in two studies, while the remaining four appeared in one study each. Three studies (Barbas et al., 2006; Folha and Barba, 2022; Olsen et al., 2019) did not use standardized tools but applied qualitative observational methods instead. The questionnaires varied widely in terms of their focus, scales, and item composition and were used in one (Golubović et al., 2022; Leung et al., 2011), two (Luttropp and Granlund, 2010; Coelho et al., 2023), or three studies (Castro and Pinto, 2015; Coelho et al., 2023; Coelho and Pinto, 2018).

When analyzing the key findings of the studies included in this systematic review, it is important to distinguish between research comparing children with and without disabilities and studies focusing solely on children with disabilities, as each provides different insights. Comparative studies highlight relative differences in participation between groups, whereas studies of only children with disabilities examine factors that influence participation within this population. Nearly half of all of the reviewed studies presented comparative evidence (n = 13, 46%) and concluded that children with disabilities exhibited lower levels of participation, including involvement and engagement, in inclusive ECEC settings than their peers without disabilities (Casey et al., 2012; Coelho et al., 2019a; Coelho et al., 2019b; Coelho et al., 2023; Coelho and Pinto, 2018; Fasano et al., 2023; Folha and Barba, 2022; Golubović et al., 2022; Hu et al., 2016; Kuutti et al., 2022; Leung et al., 2011; Nesbitt and Farran, 2022; Walker and Berthelsen, 2008). Four studies, however, did not find significant differences or reported mixed findings (Åström and Almqvist, 2022; Luttropp and Granlund, 2010; Pinto et al., 2019; Tsao et al., 2008). Additionally, Coelho et al. (2019a), Luttropp and Granlund (2010), and Walker and Berthelsen (2008) found no significant differences in time spent in activities (attendance), whereas Harper and McCluskey (2002) and Kuutti et al. (2022) did observe such differences. Overall, engagement levels were highly variable, likely influenced by the diversity of disabilities (most studies included a broad range of disability types without reporting separate results), the variety of educational settings (ECEC organization differs globally), and the measures applied (studies with different methodologies found both differences and no differences; Kemp et al., 2013; Kuutti et al., 2022; Walker and Berthelsen, 2008). Despois and André (2024) further highlighted that children’s engagement may evolve over the course of a school year, emphasizing the importance of timing and other contextual factors in data collection.

A quarter of the studies (n = 7) concluded that children with disabilities interacted with peers less often, had fewer social relationships, or were more often socially withdrawn compared to children without disabilities. Instead, they spent more time interacting with adults (Hamilton, 2005; Harper and McCluskey, 2002; Hu et al., 2016; Kuutti et al., 2022; Luttropp and Granlund, 2010; Olsen et al., 2019; Walker and Berthelsen, 2008). Fasano et al. (2023) found that children’s vocalizations directed toward peers and adults were significantly associated with their classroom engagement, which underscores the importance of providing opportunities for social interactions.

Several studies showed that children’s level of involvement or engagement—as well as their participation in interactions—varied depending on the type of activity (Coelho et al., 2019a; Coelho and Pinto, 2018; Golubović et al., 2022; Hamilton, 2005; Hu et al., 2016; Syrjämäki et al., 2023; Tsao et al., 2008). In general, participation seemed to be lower during whole-group activities (Hu et al., 2016; Kemp et al., 2013). Children with disabilities were generally more involved and engaged in structured activities (e.g., circle time, meal time), whereas the biggest differences compared to children without disabilities emerged during unstructured activities such as free play (Barbas et al., 2006; Golubović et al., 2022; Kishida and Kemp, 2006; Luttropp and Granlund, 2010; Olsen et al., 2019). In addition, Coelho and Pinto (2018) found that children with disabilities spent more time in less complex forms of social play or in activities with higher social demands. However, three studies reported higher involvement and engagement of children with disabilities during free play than in other types of activities or presented mixed findings (Coelho et al., 2019a; Kemp et al., 2013; Syrjämäki et al., 2023). An important factor influencing engagement during free play seems to be the extent of adult support provided (Coelho and Pinto, 2018; Despois and André, 2024; Folha and Barba, 2022; Syrjämäki et al., 2023).

The included studies provide various insights into ECEC contexts and identify a range of factors that influence children’s participation. These factors span the quality of interactions with peers and adults (Casey et al., 2012; Coelho et al., 2019a; Fasano et al., 2023; Odom et al., 2006), environmental characteristics (Castro and Pinto, 2015; Kishida and Kemp, 2009; Pinto et al., 2019), and children’s individual skills in areas such as language (Despois and André, 2024; Fasano et al., 2023; Harper and McCluskey, 2002; Kuutti et al., 2022), self-regulation (Coelho et al., 2019b; Coelho et al., 2023; Kuutti et al., 2022), social development (Leung et al., 2011; Odom et al., 2006; Walker and Berthelsen, 2008), motor proficiency (Harper and McCluskey, 2002; Leung et al., 2011; Walker and Berthelsen, 2008), and executive functioning (Nesbitt and Farran, 2022). Other influencing factors include hyperactivity (Coelho et al., 2023) and challenging behavior (Despois and André, 2024). Golubović et al. (2022) also discussed demographic and family-related factors, such as age (with younger children showing lower engagement), gender (with boys showing lower engagement than girls), and parental characteristics. Several studies emphasized the role of the disability type (Harper and McCluskey, 2002; Kuutti et al., 2022; Odom et al., 2006), with Kuutti et al. (2022) finding that children with self-regulation difficulties or severe disabilities showed lower participation compared to children with language difficulties in a variety of areas. Nevertheless, many studies concluded that disability status alone does not fully explain differences in participation. Instead, the presence and type of a disability seem to be part of a more complex interplay of factors (Casey et al., 2012; Castro and Pinto, 2015; Coelho et al., 2019a). In line with these findings, some studies chose to assess children’s functioning levels instead of solely relying on diagnostic labels (e.g., Castro and Pinto, 2015; Coelho et al., 2019b; Coelho et al., 2023). Pinto et al. (2019) even proposed that participation itself may serve as a better indicator for children’s need for support and adequate interventions than diagnosis alone. Åström and Almqvist (2022) identified eight clusters describing children’s participation profiles, with children with disabilities appearing in all clusters—although more frequently in those reflecting lower levels of participation.

This review aimed to provide a comprehensive overview of how participation is defined and operationalized in the context of inclusive ECEC and to synthesize the key findings from empirical studies, addressing a notable gap in the literature. The 28 included studies varied considerably in theoretical frameworks, methodological approaches, and sample characteristics. This deliberate inclusion of a broad range of studies was intended to capture the diversity of perspectives and the current academic discourse on participation in early childhood education research. Despite this heterogeneity, we were able to identify common denominators on the construct in inclusive ECEC. However, this heterogeneity also posed challenges for summarizing and comparing findings. For example, while many studies included children with global developmental delays, ASD, or speech and language disorders, children with sensory impairments and especially children with more severe and complex disabilities were studied less often, limiting conclusions for these groups. Additionally, some relevant studies may have been excluded due to the necessity of adhering to specific inclusion criteria.

As the quality assessment revealed, the methodological rigor and reporting standards of the included studies varied, which has implications for the validity and interpretability of their findings. A common limitation was insufficient detail regarding the study design and theoretical underpinning. For example, not all studies provided detailed information on the sample characteristics (e.g., disability type), nor did they consistently describe the ECEC activities examined in relation to participation. This lack of contextual detail is notable, given that participation is highly dependent on situational and environmental factors. Moreover, the possibility of publication bias should be considered, as studies reporting significant findings are more likely to be published than those with null or mixed results (Dwan et al., 2008), although this review did include studies reflecting a range of outcomes.

The included studies were conducted in 12 different countries across five continents—14 in Europe, six in North America, five in Australia, two in Asia, and one in South America (see Table 2). These countries vary in terms of their ECEC systems, levels of inclusive education implementation, and broader linguistic, cultural, and socioeconomic contexts (Dott and Licandro, accepted), which may influence the conceptualization and measurement of participation and limit generalizability. Furthermore, several studies were conducted by the same research groups, potentially giving disproportionate weight to their findings. Finally, the review was limited to studies published in English, potentially excluding valuable research from non-English-speaking or underrepresented regions, particularly from the Global South, thereby narrowing the discourse on participation in inclusive ECEC. Including grey literature and other sources could broaden the scope of available insights. Future research should aim to fill these gaps.