Introduction

In recent years, there has been a noticeable decrease in students' interest in science, which coincides with the reporting of lower levels in certain indicators of their academic performance in this field (e.g., Hsieh, 2020; Tröbst et al., 2016). This decline in attitudes and motivation towards science is happening mainly during the transition from primary to secondary school (Evagorou et al., 2024; Potvin & Hasni, 2014) and is reduced when students engage in real world problems and interact with external stakeholders like scientists (Tröbst et al., 2016). At the same time, there is a need in developing countries for skilled workers in STEM (Science, Technology, Engineering and Mathematics) fields, as projected for the coming years, increasing the pressure of the educational systems to attract more students in science related subjects. Despite the need to increase students’ motivation towards science, a disconnection persists between the science taught in schools and its perceived relevance to students' lives. Thus, many students find science education irrelevant (e.g., Zhang et al., 2022), and schools have struggled to adapt to rapid societal changes (e.g., De Zuani Cassina et al., 2023), leaving them ill-prepared to equip students with the necessary skills for a changing society. To address this gap between the demands of sectors linked to science and technology in today's societies and the lack of interest of the new generations in these areas, organizations like the Organisation for Economic Co-operation and Development (OECD), and the European Union (EU) have launched policies and initiatives including open schooling (OS) and STEM/STEAM (Science, Technology, Engineering, Arts and Mathematics) education. Although this promotion of OS by European political institutions is recent, many projects have already been or are being developed for bringing this approach into the classrooms. However, the literature on how exactly this approach is being implemented in schools is still scarce. For this reason, the aim of this study is to further explore the implementation of the OS approach as it has gained international attention.

The philosophy underpinning OS can be traced back to the ideas of John Dewey, who emphasized learning with and for the community (Sarid et al., 2024). OS is presented as an educational approach that aims to bridge the gap between formal education and society needs by opening the school to diverse stakeholders, such as families, scientists, enterprises or public institutions (Sarid et al., 2024), providing formal and informal learning opportunities. OS can be explained as innovative learning strategies which aim to open up schools to the community, to support science education through collaboration on real-world problems applications (M. Sotiriou et al., 2021) to ensure a science learning continuum, incorporating formal learning with informal learning experiences and providing a model on how to complement each other to support learning (Bogner & Sotiriou, 2023). This promotion of collaboration between formal education and informal learning experiences aims to increase the uptake of science and foster science-based careers, employability, and competitiveness.

By exposing students to real-world science applications outside the classroom, this approach can potentially support them to better understand the practical relevance of science, and at the same time it promotes critical thinking and skills associated with students’ future careers. Additionally, OS encourages schools to address local community needs by developing projects that foster community collaboration, with an emphasis on local issues that require attention and enhancing the relevance of education. Schools can therefore through OS act as agents of community collaboration with local stakeholders and integrate these activities into both curricular and extracurricular settings (Sarid et al., 2024).

Although several projects on OS have been developed to date, systematic discussions on OS remain scarce in peer-reviewed academic journals. This is especially relevant regarding the definition of educational practices linked to OS, and the outcomes of OS on students’ attitudes, motivation, and learning outcomes. This reveals a gap between the reform efforts expressed in international policies and rigorous academic discourse (Sarid et al., 2024), indicating the need for further exploration and validation of OS as an effective model for science education. Part of this greater validation could be achieved once a more precise definition and conceptualisation of this approach has been established, given that there is currently some ambiguity when it comes to defining it. This ambiguity stems, in part, from the fact that OS shares elements with other similar educational approaches, although it incorporates novel elements that make it a broader and more structurally and institutionally open approach.

OS emphasises school-community collaboration, which is also shared by approaches such as Community Schools (Heers et al., 2016) or Community-Based Learning (Crawley & Crawley, 2022). However, OS experiences aim to involve a wide range of stakeholders (schools, NGOs and associations, families, businesses, administration, etc.) that can operate at different scales (local, regional, national and/or international), so it is often linked at the institutional level to educational policies and/or networks. Approaches such as Place-Based Learning share with OS the promotion of learning through real experiences, problem solving or working with the community (Ellington & Prado, 2024), but they do not usually cover large scales, being more anchored to the local level. OS also shares with other approaches its problem-solving orientation. However, OS emphasises scientific and technological innovation to address such problems, while other approaches are more oriented towards civic engagement, community service, enhancement of local identity or sustainability (e.g., Community-Based Learning, Placed-Based Learning, educational activism, environmental citizenship, etc.). Finally, OS proposes a more flexible and transdisciplinary curriculum, while other approaches focus on adapting the curriculum, which may or may not be multidisciplinary, to local needs (e.g., Community-Based Learning) or even subject to local place and culture (e.g., Place-Based Learning).

In recent years, OS has been promoted through policies disseminated in documents such as the OECD (2020) reports that emphasize the schooling of the future, or the EU reports (European Commission, 2015), which aim to frame a series of innovative practices within science education. The report Science Education for Responsible Citizenship (European Commission, 2015) defined OS as an approach ‘where schools, in cooperation with other stakeholders, become agents of community well-being; families are encouraged to become real partners in school life and activities; professionals from enterprise, civil and wider society are actively involved in bringing real-life projects into the classroom’. Since this concept began to spread, many research projects, completed or underway, that work under this concept have emerged, such as PHERECLOS, OSHub, SALL, MOST, Make it Open, CONNECT, COSMOS, MultiPlayers or Pafse (Okada & da Matta, 2021), and it is receiving increasing attention in the academic literature (e.g., Bogner & Sotiriou, 2023; Papaevripidou et al., 2024). In this work we try to address the existing gap in science education regarding how OS is being defined, how OS is introduced as a practice in science education settings, and what are the impacts of OS on student outcomes and attitudes. For these objectives, a systematic literature review could provide valuable information, as no other systematic literature review with these objectives has been found in the databases consulted.

Research Questions and Objectives

The aim of this study is to summarize the OS approach that has been applied in science education thus far, particularly focusing on the interpretation of the term ‘open schooling’, the teaching practices associated with OS in existing literature, and the outcomes achieved. The research questions and objectives guiding this systematic literature review are:

Research question 1: What are the elements that comprise the definitions of the term ‘open schooling’ in the literature of science education?

Research objective 1.1: To analyse the constituent elements of the definitions of the term ‘open schooling’ in the literature on science education.

Research question 2: What kind of practices are used in the OS experiences reported in the literature on science education?

Research objective 2.1: To analyse the topics addressed in the OS experiences reported in the science education literature.

Research objective 2.2: To analyse the approaches and methodologies applied in the OS experiences reported in the science education literature.

Research objective 2.3: To analyse the activities and resources used in the OS experiences reported in the science education literature.

Research question 3: What are the data collection instruments used and the benefits reported in the OS experiences reported in the literature on science education?

Research objective 3.1: To analyse the data collection instruments used in the OS experiences reported in the science education literature.

Research objective 3.2: To analyse the benefits found in the OS experiences reported in the science education literature.

Methodology

Protocol and Registration

This systematic literature review has been carried out according to the PRISMA guidelines. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 methodology is an update of the QUOROM (Quality of Reporting of Meta-analyses) statement, which aimed to provide guidelines for improving the quality of systematic review reports (Athikarisamy & Patole, 2021; Moher et al., 1999). This methodology has also been used by other authors in education in recent years (e.g., Behl et al., 2022; Clunie et al., 2018; Manzano-León et al., 2021).

Eligibility Criteria

The eligibility criteria to be used in the studies selection, i.e., after the identification phase (database searches), were as follows:

Field: Only science/technology education.

Population: All educational stages (early childhood, primary, secondary, and higher education).

Context: Formal, non-formal, and informal education.

Outcomes: Theoretical and empirical studies.

Others: Publication date from January 2015 to February 2024 and English language.

Information Sources

Five databases were used for the identification phase: Web of Science (last consultation date: 14/02/2024), ERIC (20/02/2024), Scopus - ScienceDirect (20/02/2024), EBSCO (14/02/2024) and Google Scholar (14/02/2024). No filters, other than publication date and language were applied, and no filters were applied to restrict searches to titles and/or abstracts. The identification phase was carried out between January 10th and February 20th, 2024.

Search Strategy

Before starting the searches in the databases, the AI tool ChatGPT (OpenAI, 2023) was used to help in the elaboration of the search strings to be used. The process consisted of chatting with ChatGPT about key phrases related to the research questions, as shown in Figure 1. The authors analysed the lists provided by ChatGPT to see whether they had repeated or missing ideas, in order to elaborate a single list of key phrases and formulating the search strings to be used in the databases. The complete search strings can be seen in Figure 1.

Figure 1. Diagram of the Process With ChatGPT to Obtain the Search Strings for the Databases.

The search strings were entered into the databases and the files downloaded were managed in Zotero to remove duplicates and obtain a single dataset, marking the end of the identification phase.

Study Selection

The first step of the screening phase consisted of reading the titles and abstracts of the records to assess whether they fit the eligibility criteria. For this process, we used ASReview (ASReview LAB developers, 2023; van de Schoot et al., 2021), which is an AI tool for supporting the screening phase in systematic reviews (Bolaños et al., 2024). The process ends when a stopping criterion set by the researcher is reached. In this work, we set a mixed strategy (ASReview Academy Team, 2024), consisting of stopping the review after screening at least 33% of the database and identifying 30 consecutive irrelevant records. The 33% threshold was deliberately chosen as a conservative cut-off, given that previous ASReview studies reported recovering 95% or more of relevant records after reviewing around 10% (Oude Wolcherink et al., 2023) and 20% (van Dijk et al., 2023). To ensure higher recall, we opted for a more cautious approach (33%, 498 records). The choice of 30 consecutive irrelevant records was based on empirical evidence supporting heuristic stopping rules in automated systematic reviews (Jonnalagadda & Petitti, 2013; Przybyła et al., 2018). Some studies using similar mixed strategies with ASReview have shown good performance (85%–93% of relevant records retrieved) when stopping after 1%–5% of consecutive irrelevant records and reviewing 10%–30% of the database (Campos et al., 2024). Since we already committed to reviewing 33% of the data, we set the irrelevant streak at 2% (i.e. 30 records), balancing efficiency with thoroughness. Thus, the mixed criterion was justified both by prior evidence and by the goal of maximizing recall without excessive screening.

Once the stopping criterion was reached, we proceeded with the next step of the screening, the eligibility assessment, consisting of reading the documents beyond the title and the abstract. The following exclusion reasons were applied:

Reason 1. No OS approach: Documents that do not even mention OS, although they report approaches close or similar to OS, such as science/responsible/environmental citizenship, out-of-school education or Responsible Research and Innovation (RRI).

Reason 2. Online or distance education: Documents related to science education and categorized as open education, but referring to distance or online learning, or where the main objective is the students’ interaction with virtual laboratories or open scientific databases.

Reason 3. Not in English: Records without an English version.

Reason 4. No science education: Documents whose main objective is not science education, although they have some elements in common with it (e.g., parents' perceptions of the use of technology in schools, or the improvement of a programme for the academic promotion of future PhDs in STEM careers).

Reason 5. No link with formal education: Documents with experiences not linked to formal education, or where only part of the sample, and fortuitously, were students from the same class or school.

Reason 6. Not in the publication date range: Works prior to 2015.

Reason 7. EU Project not developed: Documents with proposals for European projects that were not awarded.

Data Collection Process

The data collection process was carried out with an ad hoc category system. The first version, consisted of 15 categories (see Table 1), was elaborated by all the authors. With this first version, one of the authors proceeded to analyse a sample of five documents in order to extract subcategories in an inductive way, reading the documents and extracting emergent topics by open coding from the data. The revised iteration of the system, featuring categories and subcategories, was deliberated upon by all the authors and modified, resulting in the third version of the analysis system. The third version was used to analyse a different set of documents, and thus, additional rounds of analysis (conducted by the same authors) and discussion (involving all the authors) were executed. The analysis was carried out with the software Atlas.ti v.9 and no automation tools were used. The data collection process was limited to the information contained in the published documents, and no authors were contacted for additional information.

Data Items

The category system is delineated in Table 1. It consists of 15 categories and 173 subcategories. Although not all the subcategories are included in Table 1, all of them are presented and described throughout the results section.

Table 1. Categories of the Analysis System and Their Descriptions

Risk of Bias in Individual Studies

No specific manual or automated tools were used to assess the risk of bias in the included studies, nor was any report or general judgement made about it. However, two aspects should be considered when using the results of this review. The first one is that all but one of the documents included in the review report non-experimental nature. The second one is that some of the documents analysed do not report information about the data collection instruments and/or the analysis methodology followed, so in those cases the benefits reported are the result of the authors' reflections or perceptions. In addition, many documents present different experiences of OS and do not detail to which experience or experiences the reported benefits are attributed.

Summary Measures

The only summary measure used is the frequency of occurrence of the subcategories in the documents. No summary measures of mean difference, variance or other similar measures were used.

Risk of Bias Across Studies

A systematic risk of bias assessment of the accumulated evidence across studies was not conducted. However, the authors have the following considerations which should be taken into account when using the results of this review: 1) as most of the documents report qualitative studies, there does not appear to be a high risk of publication bias in this review, i.e., publication of only significant results; 2) the fact that virtually all documents analysed report non-experimental studies presents the risk of selective reporting within studies, showing only positive results of OS experiences; 3) as this research only aims to collect information on the benefits of OS, a selective reporting of the information included within studies has been performed by the authors; and 4) inter-rater reliability analyses have not been carried out either for the screening of the records or for the categories of analysis obtained, which limits the reproducibility of the study.

Study Selection

The process for obtaining the documents to be included in the review is shown in Figure 2. The searches in the databases resulted in 2314 documents and after the screening phase 27 studies were included in the review. Although the identification phase concluded in February 2024, it was decided to include three documents that were subsequently sourced through email notifications, since the authors considered them relevant, and they satisfied the inclusion criteria. This thorough approach ensured that the review included a diverse range of relevant studies, which enhanced the trustworthiness and reliability of the findings.

Figure 2. PRISMA Flow Diagram Template (Page et al., 2021)

Results

Characteristics of the Studies

This section shows a summary of the results of the main characteristics of the 27 studies included in the analysis. All the data and the complete descriptive information on the documents can be found in Table A1 in Appendix material.

Most of the experiences reported in the documents were carried out in secondary (17) and primary (11) education. More than half of the documents (14) report implementation times equal to or greater than one year both for factual and suggested implementation times. One example of long-term OS experiences is shown in Okada (2023), such as an initiative on biodegradable plastics that was developed with 115 secondary students in Romania during the school year 2021-22. The students actively participated in scientific and educational activities focusing on plastic pollution in which they had to apply their knowledge about plastics acquired in chemistry lessons (e.g., their chemical composition or their decomposition period in nature). Regarding the research methodology used, 26 were empirical studies, mainly qualitative studies (15), while one was theoretical. However, empirical studies also include those whose main objective is to describe, compare or disseminate OS projects or experiences, even if they do not include systematized data analysis.

Results of the RQ1: Definition of Open Schooling

The descriptions of the subcategories found in the analysis of the OS definitions and their frequencies are presented in Table 2. Figure 3 shows the relationships between the subcategories (the subcategories ‘Others’ and ‘No definition’ are not represented and they have frequencies of 18 and 1, respectively).

Table 2. Subcategories Obtained in the Analysis of the Definitions of OS. Not Mutually Exclusive

Collaboration with stakeholders is present in 24 definitions of OS, and parental engagement is explicitly mentioned in 12 of them. Contextualization appears commonly alongside problem-solving in the definitions (14). Community well-being maintains strong relationships with collaboration with stakeholders (in 17 definitions) and contextualization (in 20 definitions).

Figure 3. Network Graph of the Subcategories Present in OS Definitions and Their Relationships. Elaborated With Flourish (flourish.studio).

Note: The size of the points is proportional to the frequency of occurrence of the subcategories and the opacity of the links is proportional to the frequency with which the subcategories appear together.

Results of the RQ2: Practices Used in OSTopic

Regarding the topics (Table 3), in most cases, the experiences reported were not monothematic but rather touched on several topics (e.g., vaccination, nanotechnology or genetically modified food).

The main topics addressed are environmental issues (24 documents), followed by health issues (13). In fact, in many cases environmental and health issues are addressed in tandem given their direct relationship. For example, Okada et al. (2020) reported an OS experience on whether Aedes aegypti mosquitoes, which transmit the ZIKA virus, should be exterminated. This experience was inspired by the company OXITEC and the students worked with a biotechnologist and a researcher in environmental biology. Thus, this experience merges health, environmental and biotechnological issues. The subcategory ‘Local issues, needs and challenges’ was created for a document that indicated ‘local issues’ (unspecified) as a topic, but many of the topics classified in the other subcategories addressed local issues too.

Table 3. Subcategories Obtained in the Analysis of the Topics Addressed in OS. Not Mutually Exclusive

Approaches/Methodologies

The use of the terms ‘approaches’ or ‘methodologies’ is not uniform throughout the documents. For example, open schooling is qualified as a methodology (Mulero et al., 2022), as an approach (Okada & da Matta, 2021), and also as a framework by Fluminhan et al. (2023). Therefore, in the category ‘approaches/methodologies’ we include all those teaching aspects that guide in a general way the experiences, i.e., perspectives, strategies, approaches, methodologies, frameworks, etc. The use of scientific practices and contextualization is practically generalized (Table 4), in the case of contextualization, most of them allude to real-world problems (van Poeck et al., 2024), real-life problems (Okada, 2023), or emerging local and global problems (Behrens & Torres, 2022). STEM approaches and their derivatives are commonly used in OS experiences, which makes sense in view of the orientation towards science and technology disciplines that has been given to this approach by the promoter institutions. One example of this kind of experiences is the one reported by Ragonis et al. (2023), in which a university research group presented one of its alternative energy projects to a group of students who, in interdisciplinary teams, participated in a reverse engineering process, analysing the project through the relevant areas of knowledge required. The high presence of RRI points out the relationship between this approach, which was another initiative of the European Commission (2015) that promotes the collaboration between schools and scientists (e.g., S. Sotiriou & Cherouvis, 2017), and the OS approach.

Table 4. Subcategories Obtained in the Analysis of the Approaches/Methodologies Used in OS. Not Mutually Exclusive

Table 4. Continued

Activities/Resources

The category ‘activities/resources’ includes those more concrete teaching aspects, more reduced in time, as well as the material or virtual objects used in the experiences. The experiences are focused on activities about data collection, analysis and synthesis (14), dissemination (13) and the use of ICTs (13) (Table 5). One example can be seen in Suero Montero et al. (2019), in whose study 16 students from 12 to 16 years old explored the question ‘What is science in society?’ To do so, they conducted a dozen interviews with municipality officials, teachers, peers, and family members in order to build a general picture of science at the local level. Then they presented their results on local television and online platforms (local media, messages, the centre’s website and the project's website). Other activities frequently used are discussion activities, infographics and collaborative activities with external experts (9 each). These results show that the experiences analysed seem to give special relevance to obtaining information from the community and that they also place similar emphasis on returning the results of their research to the community.

Table 5. Subcategories Obtained in the Analysis of the Activities/Resources Used in OS. Not Mutually Exclusive

Stakeholders

The most common stakeholders involved in OS experiences are companies and local businesses (22) and experts from universities and research centres (20) (Table 6). The participation of families is reported in 18 documents, and this subcategory includes both mentions to families or family members, in general, and mentions to parents. In the same way, there are 15 references to community participation, in general, either because the groups involved are not specified or because the activities were open to the public.

Most of the documents (21) report experiences in which three or more different stakeholders were involved, which gives an idea of the variety of linkages with different spheres of the community established by the OS experiences analysed. A project that involved several stakeholders is reported by McLoughlin et al. (2018), developed in Ireland with 12–13-year-old students on the necessity of all-year round availability of non-seasonal fruit and vegetables. The teacher started asking students about whether the food choices they make are sustainable, whether they knew which fruits and vegetables were in season or whether it was 'natural' to find most fruits and vegetables in supermarkets at any time of the year. Students designed a series of investigations to question ethical and sustainability issues surrounding global food production and consumption using critical data analysis and personal case studies. They engaged the local community in discussions with local supermarket managers to encourage them to offer more locally sourced products, and they also took the project home to reflect on their own family's food choices.

Table 6. Subcategories Obtained in the Analysis of the Stakeholders Involved in OS. Not Mutually Exclusive

Results of the RQ3: Benefits of Open Schooling

Data Collection Instruments

18 documents report information on data collection instruments and/or analysis methodologies used (Table 7). The use of questionnaires is predominant, mostly closed type with Likert scale (e.g., Mulero et al., 2022; Romero-Ariza et al., 2023), but there are also some mixed instruments (e.g., Okada & da Matta, 2021). Only one experimental study has been found with control and experimental groups (Suero Montero et al., 2019). Four of the nine documents do not provide information about instruments and/or analysis which, in our view, makes sense given the purpose of the works, such as theoretical analysis based on literature reviews(Fluminhan et al., 2023), exploratory studies (Okada et al., 2020) or just present initial outcomes of a project (Behrens & Torres, 2022). However, the remaining documents that do not report this information could indicate a lack of evaluation of the experiences carried out.

Table 7. Subcategories for the Analysis of the Data Collection Instruments Analysis. Not Mutually Exclusive

Benefits

As most of the documents describe several OS experiences and/or different data collection instruments, showing their results all together, it is not possible to discriminate from which experience and/or data collection instrument each result comes from. 18 documents report benefits on learning-related aspects (knowledge, skills, awareness, or knowledge of available resources), and 11 report benefits on a motivational and engagement level (motivation, interest, engagement, or attitudes) (Table 8). An example is the project reported in Romero-Ariza et al. (2023) in a project with Spanish primary students on sustainability to improve their neighbourhood. The students increased their knowledge of environmental problems and their role in addressing them, acquired environmentally friendly attitudes and behaviours, and showed high indicators of scientific literacy after the project. Eight documents also report benefits for schools, such as M. Sotiriou et al. (2021) and Okada (2023). The first authors report data from 500 schools in 11 EU countries, reporting that the applied OS approach had a significant impact on the openness of the participating schools, showing to have been highly successful in the diffusion of innovation in schools. The second author reports the results of an experience on the importance of mental health. Following the experience, the school institution showed greater commitment to the promotion of mental health and plans to create a physical space called ‘Emotional Classroom’ to support emotional well-being, and the Guidance Department will collaborate with the ‘Healthy Habits and Lifestyles’ program to design interdisciplinary activities aimed at promoting students' well-being. The creation of networks is another benefit for schools pointed out by Behrens and Torres (2022). As for the teachers, seven documents report benefits for motivation and self-efficacy, and six report improvements in their pedagogical content knowledge. In the study by Suero Montero and Oliveira Leite (2022), the participating teachers rated very positively how they felt about planning and executing activities outside the school during an OS project, with a mean score of 4.59 (SD=0.62) out of five, and in the study by Okada (2023), with 7-11 year-old students in Brazil on the pollution of a local lake, teachers found that students' questions helped them transform their teaching practices and foster the development of new skills. The authors also note that, although it was a challenge for teachers in terms of continuous learning and adaptation based on students' questions, this approach contributed to their professional growth.

Table 8. Subcategories for the Analysis of the Benefits of OS. Not Mutually Exclusive

Conclusions

The aim of this review was to examine the implementation of OS experiences in science education over the past few years. While the landscape revealed is quite varied, a certain level of agreement also appears to emerge, as the findings indicate that OS experiences are adaptable because they allow the articulation of a wide range of pedagogical resources, despite functioning under the same defining codes.

Most of the OS experiences with students analysed are carried out in secondary education (e.g., Behrens & Torres, 2022; Mulero et al., 2019), and to a lesser extent in primary education (e.g., Bogner & Sotiriou, 2023; Şardağ et al., 2023), despite the greater curricular flexibility of the latter that would allow more time to be devoted to the development of OS projects. However, it remains to be studied whether approaches such as OS and similar approaches, which encourage collaboration with researchers and STEM professionals, could help to mitigate the changes in motivation and interest in science that students experience in their transition from primary to secondary school, as reported in the literature (Evagorou et al., 2024; Potvin & Hasni, 2014).

In response to the research question 1, the literature analysed shows that OS experiences are defined as an active collaboration between the school community and various and diverse external stakeholders, highlighting the involvement of students' families, with the aim of addressing real local problems in order to contribute to community well-being (e.g., Bogner & Sotiriou, 2023; Mulero et al., 2022; Sarid et al., 2024). This shows that the experiences reported in recent years address several of the central elements that define this approach in the educational policies that have promoted it.

Regarding the research question 2, OS experiences often address several topics (e.g., Santos et al., 2023), requiring the integration of multiple perspectives through interdisciplinary approaches or addressing socioscientific issues (e.g., Okada & da Matta, 2021; Suero Montero & Oliveira Leite, 2022). The frequent inclusion of environmental issues seems to call for the need to incorporate frameworks from environmental education or education for sustainable development (e.g., Okada et al., 2020), thus pointing to an education oriented towards students' research outside the classroom on nearby problems to approach global climate challenges. To this end, data collection, analysis and synthesis activities or other scientific practices (e.g., McLoughlin et al., 2018; Papaevripidou et al., 2024) seem to help to develop the OS experiences (e.g., Okada et al., 2020).

Finally, regarding research question 3, the benefits of OS reported in the studies analysed are not limited to the school level, i.e., on students and teachers, but seem to generate positive impacts also outside the educational community (e.g., Fisker & Clausen, 2017; Fluminhan et al., 2023; Mulero et al., 2022). Nevertheless, our results show a need both to report more extensively on the results of the evaluation of OS experiences and to carry out such evaluations in a more systematic manner. To this end, it seems necessary to make efforts to develop specific instruments, such as those developed by Romero-Ariza et al. (2023) or M. Sotiriou et al. (2021).

This work has focused on the main characteristics of the OS experiences reported in studies in science education and the benefits found in the last decade. Nevertheless, literature reports possible negative aspects and challenges that this approach needs to address. One of them is the lack of specificity about its definition and application, an aspect that has been noted in the results of our review. This ambiguity was already pointed out prior to recent efforts by European institutions to promote OS and makes it difficult both to evaluate experiences rigorously and to compare them (Ahlgren & Germann, 1977). The assessment of transversal competences and the adaptation of curricula to real contexts inherent to approaches such as OS present a certain complexity that requires pedagogical innovation and constant institutional support (Okada & da Matta, 2021; Okada et al., 2024). Regarding this institutional dimension, Sarid et al. (2024) point out that debates on OS are largely absent from peer-reviewed academic journals and publications and they identify a gap between recent reform efforts expressed in international policies and reports and rigorous academic discourse. Thus, it seems necessary to advance the dialogue between policy, educational and academic institutions towards a more precise definition of OS. Teacher training is another issue that needs to be addressed, as the implementation of more open methodologies such as OS requires changes in the training and teachers are often resistant to moving from traditional practices to more collaborative and student-centred ones (Gorghiu et al., 2024; Okada & da Matta, 2021). Other difficulties in including OS in education systems are the temporary nature of the experiences and the effort they require. Regarding the former, most OS experiences depend on projects funded for a fixed period of time, which makes it difficult to ensure the continuity of OS programmes in schools once the projects have ended, as well as a sustained evaluation of the programmes over time. As for the second, the need to establish partnerships entails an overload of responsibility and/or work for the actors involved, such as families or professionals from the private sector, in addition to that of the participating teachers, who often have to develop these experiences in parallel to their regular teaching duties.

Limitations

This review cannot assess the risk of bias of the results reported in the documents included in the review, for the reasons discussed throughout the manuscript. Consequently, the benefits of the OS approach summarized in this work must be interpreted with this context in mind, acknowledging that, because of the research questions posed, the possible drawbacks of OS indicated in these publications have not been compiled and remain beyond the scope of this research study. The conceptual and practical limitations of the OS approach described in previous sections must also be taken into account, the most important being the lack of a precise and distinctive definition of OS and the lack of adequate instruments for its evaluation. Moreover, experimental or longitudinal studies are virtually absent in the literature reviewed, which affects the strength of the evidence. All these limitations currently prevent the generalisation of the findings.

Ethics Statement

This study did not require the approval of an ethics committee as it did not involve study subjects or personal data of the subjects of the studies analysed.

Conflict of Interest

The authors report there are no competing interests to declare.

Funding

This work is part of a project that was funded by the European Union under Grant HORIZON-WIDERA-2022-ERA-01-70 (nº 101093387), EU project ‘ICSE Science Factory. Open schooling for science education and a learning continuum for all’.

Generative AI Statement

As the authors of this work, we used the AI tool ChatGPT for the purpose of helping in the elaboration of the search strings to be used in the searches for the literature review. We also used the AI tool ASReview for the purpose of supporting the screening phase in the systematic review. After using these AI tools, we reviewed and verified the final version of our work. We, as the authors, take full responsibility for the content of our published work.