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). 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 η
2 = 0.34] on their content knowledge and content assessment scores (partial η
2 = 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 η
2 = 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 η
2 = 0.12); a small effect for “Discover Natural Phenomena” (partial η
2 = 0.013), small effect for “Dinosaurs and Evolution” (partial η
2 = 0.03), a medium effect for “Augmented Reality” (partial η
2 = 0.107), a small effect for “4-D Math” (partial η
2 = 0.02), and a large effect for “Hands-on in Science” (partial η
2 = 0.411). In the “Hands-on in Science” aspect, the analysis showed that the effect was less powerful in the boys’ group: (partial η
2 = 0.31), than for the girls, (partial η
2 = 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 (η
2) to quantify the effect of a trip to a space museum. They stated that large effect sizes for the scientific justifications (η
2 = 0.377) and scientific predictions (η
2 = 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.
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.
As outlined in
Table 5, 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). 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).
The reasons sites were chosen by EOC practitioners within the reviewed papers are included in
Table 8.
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.