A Systematic Review on Education Outside the Classroom: Lessons for Science EOC Practices

Abstract

The United Nations’ sustainable development goals highlight the importance of embracing our natural environment through action in education. In science education, it is therefore important to enhance our understanding of pedagogical approaches that promote Education Outside the Classroom (EOC). The aim of this systematic review is to investigate EOC methods and pedagogies and examine how they can help inform students’ acquisition of scientific knowledge and skills. In total, 157 full texts were read and considered for inclusion in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The final review included 49 empirical studies that examined EOC research between 2012 and 2021 across all disciplines. Positive outcomes are reported regarding student learning, motivation, and enjoyment, which highlight the benefits and rationale for adopting such approaches to support learning. However, a lack of longitudinal data was evident regarding the impact of the EOC experiences. This review shows that the pedagogical models underpinning the approaches to EOC were not always explicit or clearly stated. In terms of the methodological considerations, a number of gaps emerged in relation to the reporting of geographical and gender differences. We offer recommendations to implement EOC in science education and suggest areas for future research.

1. Introduction

Learning from the environment has been a part of human cultural heritage from the beginning of time in an effort to preserve and build knowledge, such as identifying poisonous foods, classifying suitable building materials, observing seasons for effective farming strategies, and experimenting with natural resources for energy generation. The United Nations’ seventeen sustainable development goals highlight the importance of embracing our natural environment, preserving culture, and replenishing our natural resources through action in education, health, social protection, and job opportunities [1]. For educators, focusing on pedagogical approaches that promote a connection with the environment, frequently referred to as “outdoor education”, seems to be one obvious strategy to align with important issues such as education about our environment, education for environmentally responsible citizenship, and sustainable development. Unlike other review studies that focus on science education (e.g., [2]) and studies exploring equity issues in out-of-school science spaces (e.g., [3]), we take a more comprehensive approach to examine learning, irrespective of the discipline, that takes place in out-of-school settings. However, given our focus on outdoor education, the majority of the studies reviewed are in fact situated in science and environmental education. By including studies examining learning in general, we aimed at gaining a more holistic understanding of learning that takes place in outdoor settings and utilises knowledge on methods and practices implemented from a range of disciplines to science education.

Outdoor education has been defined as “education about the outdoors and its many ramifications, in the outdoors, for the purpose of developing knowledge, skills, and attitudes concerning the world in which we live” [4] (p. 10). More specifically, Education Outside the Classroom (EOC from now on) encompasses the process of outdoor learning in the many different contexts of our environments today such as classrooms in urban settings, classrooms in rural settings, classrooms with few resources, and classrooms with learning challenges.

This study uses EOC as a lens to examine curriculum-based educational activities practiced outside school buildings across all disciplines, in nature (e.g., a park or forest), or in cultural settings (e.g., a museum or library) for the purpose of science learning.

This systematic review aims to enhance the understanding of EOC methods and pedagogies and how they can help inform students’ acquisition of scientific knowledge and transferable skills. More specifically, our goal is to identify, organise, and synthesise empirical research about the impacts of EOC practices on students (aged 6–18 years). A secondary goal of the review is to examine the gender and geographical differences in these impacts; methodologies used for assessing impacts; and effective tools and practices used by EOC practitioners.

Based on a systematic review, this manuscript aims to respond to the following research questions:

• What are the outcomes and impact of EOC on student learning?
• What factors need to be considered when adopting EOC practices?

In synthesizing the findings, we pay particular attention to the areas for further research; areas that are not considered or warrant further and deeper exploration. Our intention in doing so is to support future research in EOC that encompasses all areas of consideration to further our collective understanding of effective EOC practices and research. The methodological approaches that guided this systematic review are first outlined, followed by the findings and related discussion. The manuscript concludes with a set of recommendations for future research in EOC in the context of science education.

2. Materials and Methods

The following review of the literature sought to synthesise empirical evidence on Education Outside the classroom between 2012 and 2021 across all disciplines. This paper does not seek to describe the history of EOC. Rather, we are interested in learning from contemporary practices so as to inform further EOC research and related teacher practice. As a result, a 10-year window was deemed appropriate to indicate the newest sources relevant to the types of practices educators utilise to develop students’ acquisition of scientific knowledge and skills. Furthermore, given the large number of papers such a search returns, 10 years enabled relevant and recent studies on EOC to be included, within a manageable number of studies.

A selection of search terms was first identified and piloted to determine suitability in terms of yielding a broad selection of research papers that were relevant to the area of Education Outside the Classroom. These draft search terms reflected the many ways in which EOC is described in different contexts. These draft search terms (please see Appendix A for the full list of draft search terms) were piloted. Search terms that yielded non-relevant papers or papers that were too broad in their results, were excluded based on this preliminary pilot search. A systematic literature search strategy was then completed in the database Web of Science with the following search terms (

Table 1. Search terms used for European and international systematic literature review.

Search Terms Used
“Models of Education Outside the Classroom”
“Models of Outdoor Learning”
“Models of Outdoor Teaching”
“Models of Museum Learning”
“Models of Field Trips”
“Models of Informal Science Learning”
“Models of Non-Formal Science Learning”

):

In the systematic review, we searched for EOC practices in all subject areas, as key learning can be taken from approaches to EOC irrespective of the subject area. The literature was searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, as recommended for systematic literature reviews [5,6].

This review sought to identify all empirical papers across subject areas that researched EOC practices in children aged 6–18 years. Research conducted from 2012 up to the search date (October–November 2021) was included for review. The reference lists of the literature included were also checked for novel articles using citation chaining. The review included quantitative and qualitative studies from the Web of Science database.

Research eligible for inclusion was required to meet the following criteria:

• An empirical-based study.
• Explores effective EOC practices (as per the search terms).
• Focuses on and includes students aged 6–18 years (may not include all of these age groups but should be within this age bracket).
• Is published in English.
• Is published in a peer-reviewed journal.
• The following research was excluded from the review:
• Research using a university student sample.
• Theoretical papers and review articles.

The search yielded 5936 publications. As indicated by Page and colleagues (2020), the number of records identified from each database or register should be searched rather than the total number across all databases/registers. The titles and abstracts were screened for eligibility and duplicates were manually removed. In total, 157 full texts were obtained, read, and considered for inclusion. Exclusion criteria regarding these texts are summarised in Figure 1. At this stage, the majority of the papers originated from European countries, as well as the United States of America, Taiwan, and China. As a result, these broad geographical locations became the focus of this review. In total, 49 articles were included in the final review. This is reflected in the PRISMA flow diagram (Figure 1).

3. Findings

The selected research papers were reviewed and are presented under the three research questions presented previously.

3.1. What Is the Impact of EOC on Student Learning?

A number of studies explored the impact of EOC on students’ learning of a specific topic. Many studies (n = 30) found that students’ knowledge, related skills, and conceptual understanding of a topic increased following engagement in an EOC experience (

Table 2. Impact of EOC.

Impact of EOC

Examples

Student’s knowledge, related skills, and conceptual understanding of a topic increased following engagement in an EOC experience

Alonso et al., 2019; Ariosto et al., 2021; Baierl et al., 2021; Beyer et al., 2015; Bhattacharya et al., 2021; Çelik and Tekbiyik, 2016; Chen and Chen, 2018; Cotic et al., 2020; Dunlop et al., 2019; Frappart and Frède, 2016; Harris and Bilton, 2019; Horn et al., 2016; Hsu et al., 2018; Huang et al., 2019; Jose et al., 2017; Kanlı and Yavaş, 2021; Kärkkäinen et al., 2017; Kermish-Allen et al., 2019; Margolin et al., 2021; Meyerhöffer and Dreesmann, 2021; Moorhouse et al., 2019; Petersen et al., 2020; Riegel and Kindermann, 2016; Roth and Reynolds, 2020; H. S. Salmi et al., 2020; Schneiderhan-Opel and Bogner, 2021; Shah et al., 2021; Stöckert and Bogner, 2020; Thuneberg et al., 2017; Thuneberg and Salmi, 2018

). For example, ref. [7] found that the use a content-based video exchange model using an outdoor learning pedagogy increased students’ knowledge score. A study by Horn et al. [8] found that students who engaged with an experiential learning tool scored higher in terms of knowledge than the control condition.

In total, 13 out of the 30 papers that reported an EOC impact included effect sizes. Three studies report on the magnitude of effect sizes using Cohen’s d. Cohen (1988) classified effect sizes as small (d = 0.2), medium (d = 0.5), and large (d ≥ 0.8).

• Baierl and colleagues (2021) indicate that the earth education programme in their study facilitated medium to large pro-environmental shifts in knowledge (Cohen’s d 0.706–1.193) and small pro-environmental shifts in attitude changes concerning preservation (Cohen’s d 0.136–0.374).
• Bhattacharya and colleagues (2021) report that the model-based investigations of Earth’s climate in their study had a moderate effect on reasoning (d = 0.71), a large effect on participants’ ability to establish a premise (d = 1.01), and a large effect on participants’ ability to interpret evidence (d = 0.90).
• Kanlı and Yavaş (2021) report that workshops that modelled exhibits at science centres allowed for medium (d = 0.72) and large effects (d = 1.21) on participants’ conceptual knowledge.

Margolin et al. (2021) calculated effect sizes using Hedges’ g for their study involving playground physics. Hedges’ g is interpreted in a similar manner to Cohen’s d (Gaeta and Brydges 2020). They report the intervention had a small effect on physics knowledge (g = 0.38). Low effect sizes were reported for science self-concept (g = 0.14), intrinsic motivation (g = 0.02), and interest in science (g = 0.03).

In total, nine studies utilised partial eta squared (partial η²) or eta squared (η²) to report the effect sizes of EOC. For the interpretation of partial eta squared, the following conventions apply: η² = 0.01–0.05 indicates a small effect, η² = 0.06–0.138 indicates a medium effect, and η² = 0.138 or higher indicates a large effect (Cohen, 1992). Please note that eta squared is always either equal to partial eta squared or smaller (Levine and Hullett 2002).

• Kermish-Allen et al. (2019) report that students who engaged with an online platform called WeatherBlur experienced a large effect size [partial η² = 0.34] on their content knowledge and content assessment scores (partial η² = 0.24] [9].
• Horn and colleagues’ (2016) interactive tree of life exhibition facilitated small effects in relation to the learning of related terms (partial η² = 0.06), a medium effect on tree terms (partial η² = 0.07), and a small effect on tree concepts (partial η² = 0.04).
• Petersen and colleagues (2020) report their virtual field trip had a large effect size (partial η² = 0.28) on declarative knowledge [10].
• Salmi et al. 2020 report that their “Mars and Space” exhibition had a large effect on learning (partial η² = 0.792).
• Schneiderhan-Opel and Bogne (2020) state their EOC fresh water supply experience had a large effect (partial η² = 0.21) on cognitive achievement.
• Stöckert and Bogner (2020) report their waste management intervention (that included an excursion to an incineration plant) had a large effect (partial η² = 0.45) on knowledge acquisition.
• Thuneberg and Salmi (2018) report on the changes in the content areas of science exhibition contexts that their participants experienced. In relation to a change in correct answers, the following effects were reported: a medium effect for “Mars and Space” (partial η² = 0.12); a small effect for “Discover Natural Phenomena” (partial η² = 0.013), small effect for “Dinosaurs and Evolution” (partial η² = 0.03), a medium effect for “Augmented Reality” (partial η² = 0.107), a small effect for “4-D Math” (partial η² = 0.02), and a large effect for “Hands-on in Science” (partial η² = 0.411). In the “Hands-on in Science” aspect, the analysis showed that the effect was less powerful in the boys’ group: (partial η² = 0.31), than for the girls, (partial η² = 0.51) [11].
• Thuneberg and colleagues (2017) report their lowest-achieving group experienced a large effect in relation to their appreciation of the exhibition for math learning compared to learning math at school (partial η² = 0.259).
• Frappart and Frède (2016) report eta-squared values (η²) to quantify the effect of a trip to a space museum. They stated that large effect sizes for the scientific justifications (η² = 0.377) and scientific predictions (η² = 0.362) were evident [12].

The focus was frequently on the affective dimensions of learning such as motivation, enjoyment/fun, and developing a more positive attitude towards the subject matter in question e.g. [13]. The students across the reviewed articles reported higher levels of motivation (n = 9), a more positive attitude towards the subject matter (n = 7), and greater levels of enjoyment/fun (n = 6) following engagement in EOC. Interestingly, four studies identified the positive impact of the EOC experience on students’ agency, freedom, and level of self-regulation. For example, Roth and Reynolds (2020) found that the students really enjoyed the activity and their factual knowledge increased after the experience. Levine et al. (2015) [14] found that after engaging in the weeklong outdoor chemistry camp, students’ interest in STEM careers increased and they also displayed more positive attitudes towards STEM, while Chen and Chen’s (2018) [15] study found that, in comparison to the control group, the experimental group had more motivation for learning. The relevant references are outlined in

Table 3. Impact of EOC on the affective dimensions of learning.

Impact of EOC	Examples
Increased motivation	Affeldt et al., 2015;
	Chen and Chen, 2018;
	Dettweiler et al., 2017;
	Dunlop et al., 2019;
	Huang et al., 2019;
	Meyerhöffer and Dreesmann, 2021;
	Moorhouse et al., 2019;
	Orson et al., 2020;
	H. S. Salmi et al., 2020.
Increased enjoyment and fun	Affeldt et al., 2015;
	Dunlop et al., 2019;
	Hsu and Liang, 2017;
	Petersen et al., 2020; Thuneberg and Salmi, 2018; Triantafyllidou et al., 2018.
More interested in and more positive attitude towards subject	Baierl et al., 2021;
	Harris and Bilton, 2019;
	Levine et al., 2015;
	Roth and Reynolds, 2020;
	H. Salmi et al., 2017;
	Shah et al., 2021;
	Todd and Zvoch, 2019.
Increased self-regulation, freedom, choice	Adams and Beauchamp, 2018; Dettweiler et al., 2017; Dunlop et al., 2019.
	Shah et al., 2021.

.

Psychomotor outcomes were not reported; however, the importance of body movement when learning was noted [16].

Gender differences were considered in some instances; however, these studies largely targeted female students and did not always include either a mixed gender group or an all-male group for comparison purposes; see, for example, [14].

Assessment Approaches Used to Assess and Evaluate EOC Experiences

There was a range of methods and instruments used to assess the impact of the Education Outside the Classroom interventions. A large number (n = 43) employed surveys/questionnaires, some of which drew on validated instruments while others were designed specifically for the specific study e.g. [17]. Many used a pre- and post-test (n = 24) in some manner when assessing the learning outcomes or interest in a particular subject area. The quantitative methods that were employed (although some used open-ended questions) are presented in

Table 4. Quantitative assessment methods to measure the impact of the EOC experience.

Assessment Method	Examples
The design and creation of a questionnaire specific to the study with both Likert scale questions and open-ended questions	Affeldt et al., 2015; Ariosto et al., 2021; Baierl et al., 2021; Beyer et al., 2015; Chou et al., 2015; Dettweiler et al., 2017; Dunlop et al., 2019; Eren-Sisman and Koseoglu, 2019; Frappart and Frède, 2016; Hsu et al., 2018; Hsu and Liang, 2017; Huang et al., 2019; Lo et al., 2021; Stöckert and Bogner, 2020; Thuneberg et al., 2017; Todd and Zvoch, 2019.
Assessments or tests/exams on the knowledge acquired for the specific subject:	Bhattacharya et al., 2021; Chen and Chen, 2018; Giamellaro, 2014; Kanlı and Yavaş, 2021; Kermish-Allen et al., 2019; Levine et al., 2015; Margolin et al., 2021; Meyerhöffer and Dreesmann, 2021; Petersen et al., 2020; Puttick and Tucker-Raymond, 2018; Riegel and Kindermann, 2016; Roth and Reynolds, 2020; Schneiderhan-Opel and Bogner, 2021; Stöckert and Bogner, 2020; Todd and Zvoch, 2019.
Quantitative ethnography	Shah et al., 2021.
Interactive quizzes	Ying et al., 2019.
Tracking different frequencies of online interactions	Kermish-Allen et al., 2019.
The use of mobile devices in learning and assessment procedures	Nikou and Economides, 2015.

.

As outlined in

Table 5. Validated scales to measure the impact of the EOC experience.

Assessment Method	Examples
The Deci–Ryan motivation test and situational motivation test, which uses self-determination theory (SDT) to test the autonomous motivation.	H. Salmi et al., 2017; H. S. Salmi et al., 2020; Thuneberg et al., 2017.
The Raven test captures non-verbal-based cognitive skills.	H. Salmi et al., 2017; H. S. Salmi et al., 2020; Thuneberg et al., 2017.
Attitudes toward outdoor play scales.	Beyer et al., 2015.
The Environment Questionnaire and the New Environmental Paradigm scale.	Baierl et al., 2021.
Scientific process skills test.	Çelik and Tekbiyik, 2016.
The ARCS instructional materials motivational scale. ARCS is an instruction model that focuses on motivation within the subcategories of attention, relevance, confidence, satisfaction.	Chen and Chen, 2018.
Intrinsic value and self-regulation in the Motivated Strategies for Learning Questionnaire (MSLQ) and the Immersive Experience Questionnaire (IEQ).	Cheng and Tsai, 2020.
The Basic Psychological Needs (BPN) Questionnaire.	Dettweiler et al., 2017.
Short form of the Questionnaire on Current Motivation (QCM).	Meyerhöffer and Dreesmann, 2021.
Trends in International Mathematics and Science Standards.	Cotic et al., 2020.
Nature of Science Assessment Scales.	Eren-Sisman and Koseoglu, 2019.
Two Major Environmental Values Model (2-MEV).	Schneiderhan-Opel and Bogner, 2021.

, a number of studies used validated scales to measure the impact of the EOC experience (references are for the papers that used these scales, not the scale reference).

The studies also drew on qualitative approaches (

Table 6. Qualitative methods to measure the impact of the EOC experience.

Assessment Method	Examples
Interviews	Adams and Beauchamp, 2018; Ariosto et al., 2021; Bhattacharya et al., 2021; Çelik and Tekbiyik, 2016; Chou et al., 2015; Dunlop et al., 2019; Ghadiri Khanaposhtani et al., 2018; Giamellaro, 2014; Harris and Bilton, 2019; Kanlı and Yavaş, 2021; Moorhouse et al., 2019; Orson et al., 2020; Puttick and Tucker-Raymond, 2018; Triantafyllidou et al., 2018.
Analysis of students’ work	Bhattacharya et al., 2021; Ghadiri Khanaposhtani et al., 2018; Giamellaro, 2014; Harris and Bilton, 2019; Kärkkäinen et al., 2017; Kermish-Allen et al., 2019; Puttick and Tucker-Raymond, 2018.
Observations	Affeldt et al., 2015; Ariosto et al., 2021; Dunlop et al., 2019; Ghadiri Khanaposhtani et al., 2018; Giamellaro, 2014; Harris and Bilton, 2019.
Video recording	Adams and Beauchamp, 2018; Ariosto et al., 2021; Chou et al., 2015; Puttick and Tucker-Raymond, 2018.

). The most common qualitative approaches used were interviews/focus groups (n = 14), analyses of students’ work/drawings (n = 7) [18], observation protocols (n = 6), and video recording and analysis (n = 4).

The qualitative methods that were used included those included in Table 6.

As can be seen above, the reviewed studies used a plethora of various assessment methods to examine the impact of the EOC interventions on students’ learning. The assessment methods were based on the aims of the intervention and therefore could be very specific to the individual research project. A few studies examined the knowledge gained using a variety of pedagogical approaches; therefore, they utilised assessment-based tests most frequently, as outlined in the above citations.

The studies that utilised the validated measures were very specific in their aims, and therefore, were able to find and use the scales listed to assess for specific elements, such as motivation to engage with the science museum exhibits and values-based components. In addition to the tests, many studies were interested not only in the academic outcomes, but also in the participants’ enjoyment and therefore drew on a range of research instruments, qualitative and quantitative to answer the research questions.

Overall, these findings indicate that a range of methods and instruments are used to assess the impact of the Education Outside the Classroom interventions. The lack of longitudinal data suggests the need to focus on the long-term evaluation of science outside the classroom practices. Some studies did assess the participants over a six-month follow-up; however, there was a lack of data to identify the longer-term implications of the EOC practices. For example, this was particularly evident in the studies that utilised camps and programmes for girls whose aim was to increase their interest in science subjects and hopefully lead them towards a STEM career.

3.2. What Factors Need to Be Considered When Adopting EOC Practices?

All of the reviewed papers reported that their EOC experience was a useful model to be implemented in classrooms. Many highlighted how the techniques they implemented can be used in any subject [8,15,19,20,21,22].

This research question considers the reviewed articles in terms of the sites used to conduct EOC, adoption of pedagogical models, length of the interventions, embedding pre- and post-learning, support for professional learning opportunities in EOC, and assessment methods.

3.2.1. Selecting an EOC Site

The reviewed papers focused mainly on field trips (n = 25) and museum learning (n = 14). The papers focusing on museum trips frequently included trips to science centres (see, for example, [23,24]) and planetariums [25]. Field trips were used in many countries to enhance and facilitate learning across primary- and secondary-level school groups. These fieldtrips frequently focused on outdoor learning in forests [7] or national parks [26] or visits to sites such as water treatment plants [27]. Other studies specifically focused on summer camp experiences (n = 4; see, for example [14,28]).

In some contexts, the students were either unable to access actual sites and virtual reality was used to provide them with a “realistic” learning environment in an online forum (n = 4) (see, for example, [29]) or virtual reality was used to supplement onsite learning (n = 7) (see, for example, [22,30]). However, EOC involving the use of technology was at the mercy of the hardware, internet network, and programme working as it should, which did not always happen [15]. Augmented reality was often used to either support or replace EOC practices through the development and/or provision of computer programmes and apps (n = 10) (see

Table 7. Augmented reality and EOC practitioners.

Impact of EOC	Examples
Augmented reality to either support or replace EOC practices	Ariosto et al., 2021; Shah et al., 2021; Moorhouse et al., 2019; Huang et al., 2019; Cheng and Tsai, 2020; Chou et al., 2015; Ying et al., 2019; Petersen et al., 2020; Lo et al., 2021; Triantafyllidou et al., 2018

).

The reasons sites were chosen by EOC practitioners within the reviewed papers are included in

Table 8. Reasons sites were chosen by EOC practitioners.

Reasons EOC Sites Were Selected	Examples
Having a direct relation to the subject matter	Adams and Beauchamp, 2018; Çelik and Tekbiyik, 2016.
Real-life learning environments	Chen and Chen, 2018; Fisher-Maltese et al., 2018.
Making connections with students’ future career paths	Affeldt et al., 2015; Levine et al., 2015; Shah et al., 2021.
Providing authentic experience of issues	Kärkkäinen et al., 2017; Riegel and Kindermann, 2016; Stöckert and Bogner, 2020.
To consolidate learning for abstract concepts in subjects	Frappart and Frède, 2016; Kanlı and Yavaş, 2021; Salmi et al., 2020.

.

3.2.2. Adopting a Pedagogical Model

The pedagogical approaches to EOC adopted in the reviewed studies placed a strong emphasis on learner-centred experiences (see, for example, ref. [26]), collaborative learning activities [31], play-based learning [16,32], games [33], and hands-on learning and peer mentoring [34].

A number of the studies (n = 17) focused on providing students with experiential learning within outdoor settings. Within this, Kolb’s Experiential Learning Cycle (1984) was the most used individual pedagogical model underpinning the reviewed papers [21,35,36,37,38].

A number of studies (n = 15) aimed to engage the students in EOC practices which provided them with hands-on, inquiry-based, or student-centred learning on a particular topic. Inquiry-based learning was viewed through various lenses and labels, such as community of inquiry [39], socio-scientific issue-based inquiry learning [40], inquiry-based out-of-school setting [25], inquiry-based science education (IBSE) [27], and 5E model of inquiry-based learning [41]. However, in some studies, inquiry-based or student-centred approaches were mentioned as the underpinning pedagogical model with little reference to how these models were embedded in the studies (n = 6).

A number of the papers were vague about the pedagogical model that they were using, and some did not report a model at all (n = 11). In most of the articles reviewed, it was evident that a set of “steps” were implemented in the outdoors that contained pedagogical reasoning but were not yet defined or presented as a formal pedagogical approach [24,42,43,44]. This was particularly evident in the international examples that focused on technology-assisted learning. Within such papers, instructional strategies, systems architecture, and content were the focus of the intervention as opposed to the pedagogical underpinnings; see, for example, [15,19,20,22].

3.2.3. Embedding Pre- and Post-Learning

A particular type of practice that emerged from this systematic review was the use of in-class learning prior to engagement in the Outside the Classroom activity; for example, [37,45]. Some studies reported the importance of having both pre-planning and post-visits/reflections to solidify learning [38]. This appeared to prepare both the teachers and students for the outdoor experience and allowed them to build on their learning. In one study, Ariosto and colleagues [43] structured the learning experiences so that every outdoor activity was connected to pre- and post-in-class learning, that they termed the in-out-in methodology [43].

The pre-learning reported in the studies reviewed mostly consisted of the students and teachers familiarising themselves with related background material or gathering resources that may be needed for the site visit (n = 26). The post-learning activities were focused mostly on a reflection and discussion of the learning that took place onsite (n = 17) and were not as common as the pre-learning activities.

The importance of pre- and post-learning, within Kolb’s Learning Cycle, was emphasised across a number of the reviewed articles; e.g., [24,38]. Without this, some students may not value the experience as a learning activity and the knowledge gained may fade quickly. Many of the studies described supplementary materials that were given to the teachers or students that could be used to support pre-/post-learning. However, these were not a mandatory part of the Education Outside the Classroom experience (n = 11).

There was a broad range in terms of the duration of the interventions across the reviewed articles. These ranged from a one-hour trip to a museum [37], to a day trip [21,40], to a multi-day trip [46,47], to a weeklong summer camp [48].

Other studies specifically focused on summer camp experiences for 1 or 2 weeks (n = 4; see, for example, [14,28]. Orson and colleagues [49] described an outdoor adventure education programme where instructors took students out into the wilderness for between one week and 2 months. All the participants reported positive outcomes regarding the dependant variables they measured, and it appears that the students enjoyed the Education Outside the Classroom regardless of its duration.

There are many considerations when assessing the duration of interventions such as the socio-economic burden for families and cost implications for longer interventions [22]. One study highlighted how the researchers could not complete follow-up surveys to assess longer-term learning due to the school holidays, which indicates that the timing of interventions and data collection is also an important point to consider [48].

Another finding from the reviewed studies was that some researchers noted the importance of iterative visits to a site [32,50,51,52].

Some studies developed a digital tool to be used in a museum and outlined the importance of revisiting the museum to use the same digital tool more than once to promote life-long and sustainable learning [20,50]. Similarly, some of the reviewed studies described sequences of lessons that were designed around Education Outside the Classroom experiences, which took place weekly over a number of weeks [16,53,54].

3.2.4. Supporting Professional Learning Opportunities in EOC

Providing teacher development to enable educators to effectively lead the EOC experience was noted. A few studies (n = 7) provided evidence of supporting the teachers through specific training with an aim to enable them to guide students’ learning during the EOC activities; see, for example, refs. [39,52,55]. These studies viewed this as integral to the students’ experience and their learning outcomes [9]. Other studies acknowledged that educator training is needed to support effective EOC practices [21,23,25,47]. However, the majority of the studies (n = 32) make no reference to supporting educators with professional learning opportunities relevant to the intervention. The remaining studies (n = 6) had researchers or trained personnel onsite that facilitated the Education Outside the Classroom, resulting in the class teacher playing a limited role.

In relation to the studies where the informal educator at a site led the onsite activity, it was reported that this can lead to varied instructional types that may not align with the planned learning outcomes for the activity. For example, Karnezou and Kariotoglou [56] conducted a study in relation to science museum educators’ inquiry practices; they reported that the informal educators used approaches across the entire spectrum of inquiry from traditional to teacher-centred and from guided to open inquiry, but lacked any theoretical background on the inquiry. They also reported that the informal educators typically gained information about instructional practice from conversations with other informal educators. This indicates a missed opportunity to use the professional expertise of the classroom teacher.

As with any study or systematic review, certain limitations exist. Firstly, the search terms and search engines used may not have captured all of the relevant articles. Human error may have occurred, particularly early on in the process when dealing with a large number of articles. The focus on European countries and two dominant examples may have resulted in relevant articles, conducted within other jurisdictions, not being included in this review. Another limitation is that this review consisted of studies published in English. The initial search of the research papers found that the majority of the papers originated from European countries, as well as the United States of America, Taiwan, and China. Given the time constraints, these broad geographical locations became the focus of this review so as to support a coherent frame regarding location and focus. This may have resulted in relevant articles conducted in other jurisdictions not being included in this review.

4. Conclusions and Recommendations for Future Research

The aim of this systematic review was to enhance the understanding of EOC methods and pedagogies and how they can help inform the acquisition of knowledge and transferable skills in science disciplines. The positive outcomes regarding student learning, motivation, and enjoyment reported within this systematic review highlight the benefits and rationale for adopting such approaches to support learning. The fact that EOC can be effectively implemented and embedded across a range of subjects, including science, is a positive finding for future curriculum initiatives. A number of gaps emerged from the reviewed articles, however, and these warrant consideration in order to support the effective and sustainable use of EOC in the future. These include an explicit and clear use of specific pedagogical models and the related embedding of pre- and post-learning; support for and focus on the professional learning of teachers; as well as methodological considerations that may inform our understanding of the impact and outcomes of EOC practices. This paper now concludes with a consideration of each of these.

4.1. Pedagogical Models and Related Pre- and Post-Learning

Based on these findings, a key area of consideration to support the development of EOC practice and research relates to relevant pedagogical models. The pedagogical models underpinning approaches to EOC were not always explicit or clearly stated in the reviewed articles. The majority of the papers focused on describing their particular teaching strategies without associating it with a specific pedagogical model. The nuances of applying pedagogical approaches used in formal settings to EOC settings is therefore not captured. Consequently, the principles behind pedagogical approaches to EOC are deficient in the literature reviewed. This is problematic, as Glackin [57] argues that the application of pedagogical practice across settings in unfamiliar contexts is not automatic, as teachers’ apprehensions related to the management of students in contexts outside the classroom can elicit a more assertive and controlling practice than is usually evidenced in normal classroom practice [57]. The way in which pedagogy is applied in EOC contexts needs to be further understood to enhance practice.

The previous research published on the role of pedagogical models in informing practice calls for the need to develop pedagogical models in line with new emerging contexts so that these learning contexts can be methodically engineered and allow for advancements formed on evidenced-based learnings [58]. Pedagogical models were frequently ignored or not explicitly reported within the reviewed articles. This finding indicates the need to define pedagogical models and differentiate from teaching strategies so that there is a shared understanding among EOC researchers. A recommendation of this study is the need for researchers to align their practice with a pedagogical model. The absence of a pedagogical model in this field hinders our understanding of how learning occurs in EOC contexts.

The findings from this systematic review also highlight the importance of embedding EOC activities into classroom practice with pre- and post-learning activities. Allocating time before the EOC activity to design pre-activities can familiarise students with the general area of study related to the site. Aligning with the work of social constructivists such as Piaget, Vygotsky, and Bruner, it is important to utilise a series of activities that transcend the formal and informal contexts, facilitating students in constructing and reconstructing their knowledge of concepts and capitalizing on their learning potential pertaining to the EOC activity [59] across subject areas.

4.2. Methodological Considerations: Longitudinal, Geographical, and Gender

A number of gaps emerged in terms of the methodological approaches and focus. The lack of longitudinal data limits the conclusions one can draw regarding the impact of any EOC experience. Shirilla et al. [60] argue that longitudinal data and multilevel modelling facilitate a greater understanding of pupil skill development and is necessary to progress our understanding of EOC learning outcomes [60]. It is important that long-term effects are not assumed; rigorous evaluations through long-term follow-up benefit education research [61] and should be applied to the EOC field.

Gaps were also evident in relation to the reporting of analysis relating to participants across various countries. Intercountry differences and their role in learning should be explored to disentangle these complexities in future studies relating to EOC activities. It is argued by Planel [62] that national cultural values are more significant for learning than pedagogical styles. Geographical differences were not considered in the evaluation approaches, most likely due to the fact that studies tended to consist of one cohort of students within a specific context. From a science education perspective, the intended science curriculum, the enacted science curriculum, and the assessed science curriculum [63]; national polices, the quality of the resources (teachers, time, materials), and societal norms may differ in a particular country. Each of these variables may influence the manner in which EOC is conducted. It is important to research EOC practice across regions to inform potential constraints and opportunities in various countries.

This study has also identified the lack of research exploring the impact of EOC activities using mixed-gender groups rather than female-only groups. Comparative research rather than reporting on female-only outcomes will allow for a greater depth of understanding of EOC projects. Gender equality in education is an important aspect of the 2030 Agenda for Sustainable Development. The United Nations (UN) promotes the role of education in the Sustainable Development Goals (SDGs); Goal 4 aims to ensure inclusive and equitable quality education for all [64]. However, from a science standpoint, biased gender norms still prevail and can reinforce the stereotype that females are lacking in the capabilities to participate in STEM activities [65]. It is important that EOC activities are reviewed and researched to indicate if females experience particular obstacles when engaging with activities to inform best practices to promote female students’ engagement with EOC activities and promote inclusive learning practices.

4.3. Professional Learning

The findings from this systematic review indicate the importance of teacher development to support EOC practices and how such things are frequently overlooked. Firstly, teachers need to be supported to effectively lead the pre- and post-learning to ensure students’ learning is effectively consolidated from the EOC experience. Coll et al. [65] report that the teachers in their study were interested in completing professional development related to planning for pre- and post-EOC activities as they indicated that they lacked this type of professional development. Secondly, teacher professional development could support teachers to lead the entire EOC experience, i.e., pre-, onsite, post-learning. This would mean that teachers are not solely relying on an informal educator onsite to lead the onsite learning. It is recommended that providing science teachers with professional development to lead onsite visits so that they include students’ ideas and informal educators’ discipline knowledge could support the sustainability of EOC practices in schools [65].

If a goal of education is to develop methods and pedagogies that can help inform students’ acquisition of scientific knowledge and transferable skills, then perhaps a consideration of the above for future EOC research and practices could further improve students’/teachers’ experiences of EOC, the related outcomes, as well as EOC researchers’ understanding of good practice in terms of EOC.