Within the past 20 years, Outdoor Education Programmes (OEPs) in general have been reported to show a number of positive effects on personal and social development, physical activity, academic achievement and leadership skills for a wide range of participants and age groups [1
With a more specific focus on education within the school context, regular compulsory school-based and curriculum-based outdoor education programmes seem to have several positive effects on students’ physical activity levels [4
], mental health status [5
], social competences and relations [6
], and academic achievement [8
An all-encompassing definition of outdoor education is scarcely possible due to different meanings, understandings and practices within various research areas, countries and cultures [9
]. Common terms include: learning outside the classroom, udeskole, friluftsliv, outdoor adventure education and forest school. In general, outdoor education can be described as teaching and/or learning and/or experiencing in an outdoor and/or out-of-school environment. The content of learning and teaching is therefore different and depends on the general aim of the programme, the target group and the outdoor setting, e.g., the gaining of knowledge in natural sciences; increased PA (physical activity), leadership skills, personal and social development; survival skills; and improved skills in relation to nature-oriented sports.
In contrast to these more general outdoor education programmes, we have concentrated on programmes that are embedded within the curriculum and are conducted regularly within the school schedule. These programmes focus on student-centred classes and interdisciplinary subjects, hands-on learning, possibilities to explore and experience oneself and the environment, and the use of natural and cultural places as a “classroom” [10
]. Regular school-based and curriculum-based outdoor education programmes are still a rare phenomenon—with the exception of the grassroots movement of udeskole/uteskole in Scandinavia [12
] which has increased during the last decade. It shows that, for example, 17.9% of all public schools and 19.4% of all private schools in Denmark participate in regular outdoor teaching [13
]. However, research results regarding those programmes are often only based on case studies using an arsenal of different methodological approaches.
Nevertheless, recent educational school reforms can be observed in several countries. The Danish reform “Improving the Public School” explicitly aims to increase PA during the school day; a longer school day with a special focus on learning, motivation and well-being; and working more closely with local sports clubs and cultural centres [14
]. Recommendations to teach several curriculum content areas outside the classroom can be found in the new regional curriculum in Bavaria, Germany [15
]. Furthermore, a shift towards multi-disciplinary, phenomenon- and project-based teaching was projected within the “National Core Curriculum 2016” in Finland [16
]. Well-structured and curriculum-integrated outdoor education programmes could therefore offer great opportunities in helping to achieve the above-mentioned objectives.
In the last decades, six important reviews and meta-analyses in the field of outdoor education have been published [1
]. Rickinson et al. [2
], for example, set a wide focus on outdoor learning by evaluating the impact of: (i) fieldwork and visits; (ii) outdoor adventure activities; and (iii) school grounds and community projects. The authors summarised diverse benefits for each category, e.g., an increase in PA and academic achievement, development of social skills and a favourable attitude towards the environment. The recent systematic review of Fiennes et al. [20
] partially updated the work of Rickinson et al. [2
] by analysing primary research studies on outdoor learning from the UK that have been published since 2003. Similar to the conclusion of Rickinson et al. [2
], most of the studies showed positive effects on a wide range of outcomes. The main study topics were still adventurous and residential activities while only a few studies were strongly linked to core curriculum subjects.
Only one review took a close look at the context of regular outdoor education within the school curriculum. Waite, Bølling and Bentsen [1
] compared studies on Danish udeskole and English forest schools with a focus on purposes, aims, pedagogy, content, outcomes and barriers. The authors especially highlighted that both concepts seem to support children in their social and academic achievement, as well as their physiological and psychological well-being.
The existing reviews and meta-analysis in the wider field of outdoor education give a valuable overview on outdoor education research and practise. However, the literature shows a wide range in the intervention length, target and age groups, programme approaches, and the methodologies used. Three publications analysed programmes in the context of Outdoor Adventure Education/Outdoor Adventure Programming [3
]. Two reviews set a very wide [2
], and one review a narrow [1
], focus on different OEPs within the school context. In addition, in most of the reviews the included primary studies are limited to selected countries. Only one review [20
] used a systematic approach with respect to approved guidelines, i.e., the Reporting of Primary Empirical Research Studies in Education (REPOSE) Guidelines [21
], and two reviews were not published in peer-reviewed journals [2
Our purpose was to summarise studies on regular compulsory school- and curriculum-based outdoor education programmes for participants aged 5–18 that had been published in peer-reviewed journals. We aimed at: (i) categorising and evaluating reported outcomes; (ii) assessing the methodological quality of the included studies; and (iii) discussing possible benefits on students’ development by such programmes.
To identify and analyse the existing literature on regular compulsory school- and curriculum-based outdoor education programmes, we chose to endorse a systematic review approach. Systematic reviews in the context of education were, however, criticised by several authors [22
]. It is concluded that one has be aware of the respective possibilities as well as limitations a systematic review can offer. Therefore, we see our work in relation to the model of education research developed by Andrews [22
]. According to this model, we tried to summarise what is published and what methodological approaches were used, to identify the gaps and methodological shortcomings in the reviewed studies [22
]. We conducted the systematic review in accordance with the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines [22
]. The PRISMA guidelines are a well-accepted tool for systematic reviews and meta-analyses, they provide a valuable overview on how to structure the research process and help authors to account for transparency, validity and reproducibility.
2.1. Search Strategy
On 8 April 2016, we searched through the electronic PubMed, Scopus, Education Source, ERIC, Green File, PsycARTICLES, SPORTDiscus and SocINDEX databases for English and German language peer-reviewed journal articles. The search string included two components: “objective” and “setting”. Whereas “objective” represented relevant terms in respect of the synonyms for outdoor education programmes, “setting” described the defined educational environment. We used the following search terms for “objective” and “setting”:
Objective: “outdoor education”, “outdoor learning”, “outdoor teaching”, “learning outside the classroom”, “out-of-classroom”, “experiential learning”, “expeditionary learning”, “udeskole”, “uteskole”, “friluftsliv”, “forest school”, “nature school”, “environmental education”, “place-based education”, “Draußenschule”, and “Draussenschule”.
Setting: “school” and “curriculum”.
We used Boolean search operators, parentheses, search fields and asterisk according to the database specifications. Furthermore, we screened reference lists and citations of included articles to identify additional relevant studies.
For a detailed protocol and search strategy, please refer to our registered and published protocol under the International Prospective Register of Systematic Reviews (PROSPERO) Number: CRD42016033002. These documents are also available under Supplementary Materials
2.2. Eligibility Criteria
We only included studies meeting the following eligibility criteria:
All types of study designs (e.g., control group design, quasi-experimental design, and case studies);
Any type of formal school- and curriculum-based outdoor education programme involving children and adolescents (5–18 years);
Regular weekly or bi-weekly classes in a natural or cultural environment outside the classroom with at least four hours of compulsory educational activities per week over a period of at least two months; and
At least one reported outcome on a student level.
No restrictions on publication periods were given.
2.3. Selection Process
Two independent reviewers (CB and GL) gradually screened all the titles and abstracts of studies identified for eligibility according to the criteria. Based on given information within the titles and abstracts, we made decisions about inclusion or exclusion. For studies that looked as if they would fulfil the inclusion criteria, we screened the full texts. If insufficient information was given in the abstract in order to make a clear exclusion decision, the full text was also screened. Any disagreements between reviewers were resolved by discussion. Both reviewers carefully documented their results after each step. We contacted the corresponding authors of 30 studies and requested additional information about the intervention and analyses procedures.
Both reviewers screened the reference lists and citations of included studies listed in Scopus using the same procedure to identify additional relevant studies.
2.4. Data Extraction
For each included study, we extracted data using a piloting form in respect to the required items. When essential information was not available from the full texts, we asked the corresponding authors to provide more information. Extracted data included:
Study characteristics: Citation, author, date of publication, journal, study-design, and country;
Population: Age, gender, sample size, and type of school;
Intervention characteristics: intervention and data acquisition period, and amount of intervention;
Methodology and analytic process.
Reported outcomes and main results.
Barriers and limitations.
Information for assessment of the risk of bias; and
Source(s) of research/project funding and potential conflicts of interest.
2.5. Analysis and Synthesis
Options for statistical quantitative analyses, including, risk ratios and standardised mean differences, were limited due to the heterogeneity of study designs, the range of measured outcomes and the overall small number of included studies. We therefore firstly provide a flow chart on the search and selection process and three tables presenting the main descriptive characteristics as well as the reported main outcomes of the included studies. Secondly, we qualitatively describe the most important outcomes of the studies in a narrative synthesis. Thirdly, we present results of the methodological quality assessment of included studies both in tables and narrative text.
2.6. Methodological Quality Assessment
Two reviewers (CB and GL) assessed the methodological quality of included studies. Additionally, one more independent reviewer (FM) had to specifically evaluate one article [23
] which had been included in the review, due to the authorship of GL and UD who are part of the review team. Any disagreements between the reviewers were resolved through discussion and by referring to a third reviewer (UD). The quality of quantitative studies was appraised using the Child Care and Early Education Research Connections (CCEERC) Quantitative Research Assessment Tool [24
]. The quality of qualitative studies was appraised using the Joanna Briggs Institute (JBI) Checklist for Qualitative Research [25
]. Both tools were used for studies using quantitative, as well as qualitative, methods. For each tool, an overall rating was conducted based on the given assessment criteria. Quantitative studies were rated on 12 questions using a scale: 1, 0, −1, and n/a (not applicable); to account for completeness one question on research ethics was adapted by the JBI Checklist for Qualitative Research. Qualitative studies were rated on 9 questions using a scale: y (yes), n (no), u (unclear), and n/a (not applicable). One item was excluded due to inappropriateness within the research field. For further analyses, we adjusted the qualitative scale similar to the quantitative scale to the level of 1 (y), 0 (u), −1 (n), and n/a. For both quantitative and qualitative studies, an overall rating is presented in Appendix A Table A1
and Table A2
with mean values and standard deviations. Based on the mean values, we provide an overall rating regarding the categories low, moderate and high methodological quality. The cut-off values are defined as follows: low = M < 0.30; moderate = 0.30 ≤ M ≤ 0.60; and high = M > 0.60. They are based on theoretical assumptions in relation to methodological quality. Our approach, including the cut-off values based on the mean values, should be seen as a relative rating in relation to our data to provide a comparison of methodological quality. To our knowledge, no other rating system is available in relation to the applied tools. No studies were excluded from the review based on their methodological quality assessment results to ensure that all the potential valuable results are presented [26
We aimed at systematically reviewing the current state of research on regular compulsory school- and curriculum-based outdoor education programmes. Specifically, we categorised and evaluated reported outcomes of 13 included studies and rated their methodological quality.
4.1. General Aspects
The current state of research is relatively small with only 13 identified and evaluated studies. This can partly be explained by the fact that outdoor education research is quite a young field of research, although, with a rising number of publications within the last years. The small number of included studies can also be attributed to the fact that efforts to conduct regular curriculum-based outdoor teaching face many barriers. Waite, Bølling and Bentsen [1
] summarised the cost of transportation and extra teachers, travel-time, a crowded curriculum and teacher qualifications as main obstacles for more outdoor learning projects in schools in the UK and in Denmark.
We also applied certain inclusion criteria, such as a minimum intervention length of eight weeks. By further opening-up these criteria, more studies could naturally have been evaluated, but this would have simultaneously led to a renunciation of the comparability of the assessed studies and outcomes. Waite, Bølling and Bentsen [1
], for example, therefore chose different inclusion criteria—less strict concerning, e.g., age group, intervention duration, publication type—and thus compared 39 similar studies concerning school-based outdoor education programmes. Compared to the related field of Outdoor Adventure Education/Outdoor Adventure Programming, the aforementioned literature reviews and meta-analyses reviewed several studies, e.g., 96 studies regarding the overall effects of adventure programmes [3
], and 43 studies concerning outdoor adventure programmes for adolescents [19
]. This can also be seen as an indication that more studies on regular compulsory school- and curriculum-based outdoor education programmes are needed, in order to gain a deeper understanding of the possible benefits.
4.2. Methodological Quality Assessment
The methodological quality assessment for most of the studies yielded moderate results.
Particularly, those results of studies with moderate or low methodological quality have to therefore be considered with caution. Apart from that, some important specific circumstances regarding the included studies have to be considered. Due to the nature of educational interventions, not all requirements for preventing possible methodological bias (e.g., randomisation, a high number of participants) can be fulfilled in practice and we applied two relatively strict assessment tools. In contrast to most natural science domains, formal ethical approvals are still not obligatory in some educational and sociological domains. Furthermore, official ethic committees still have to be established to a certain extent. Another explanation could be that researchers are incidentally unaware of the importance of such formal ethical issues. Furthermore, the aim of most (case) studies included in this systematic review was rather to explore the field and to describe specific (rare) cases, instead of giving the opportunity to generalise the results gained to a wider population. As mentioned above, several studies do show a lack of methodological quality. Although the methodological quality of research studies is not the main focus of this review—and one should not overestimate it when considering the possibilities of conducting studies in educational settings—these ratings can be seen as indicators for detecting shortcomings in this particular scientific field, and this is in concordance with results of the review by Scrutton et al. [18
]. The authors examined studies in the related field of Outdoor Adventure Education, focusing on personal and social development. They stated that, frequently, the sample sizes used were too small, and went on to discuss the questionable usage and handling of questionnaires, as well as the statistical management of variables. Scrutton and colleagues [18
] requested that future research should be carefully designed with regard to methodological rigour if the researchers’ aim is to actually inform and change educational policy.
Certain results must therefore be interpreted with respect to the study design used and its corresponding possibilities and weaknesses as regarding generalisability, validity and reliability.
4.3. Learning Dimensions
The presented results in the category of learning dimension, reported by seven studies [7
], illustrate one main focus of the current research in the field of regular compulsory school- and curriculum-based outdoor education programmes.
According to the results on learning dimensions, students particularly seem to benefit in terms of an improved academic performance in several subjects, improved skills in transferring the knowledge gained to real life situations. In addition, two studies [27
] mentioned possible benefits on aspects of students’ learning motivation, i.e., learning as fun and a desire to learn. Considering that learning motivation can be an important factor for academic success [35
], and some studies in outdoor education settings [36
] have already analysed motivational aspects of short-term interventions, this could possibly be a promising approach for future research.
The methodological quality for studies reporting on learning dimensions, however, is rated as moderate [7
] except for one study which is rated as low [31
]. Due to the methodological weaknesses, the reported results have to be considered with caution. However, they are in concordance with different literature reviews and meta-analyses concerning general outdoor education. Waite, Bølling and Bentsen [1
] mentioned that regular udeskole enhances learning outcomes. Rickinson et al. [2
] highlighted the benefits of school grounds/community projects on students’ science process skills as well as the impact of fieldwork and visits on students’ long-term memory and higher order learning. Furthermore, Cason and Gillis [19
] found an average effect size of 0.61 (n
= 10; SD = 1.527) of outdoor adventure programmes on adolescents’ grades and Hattie et al. [3
] mentioned that “adventure programs enhance general problem solving competencies”, understood as a subcategory of academic performance (ES = 0.45; n
= 23; CI = 0.23 to 0.67).
Taking into account these indications and respective methodological shortcomings, more high quality-studies are needed to further examine possible effects of regular outdoor classes on students learning dimensions.
4.4. Social Dimensions
The presented results in the category of social dimension, reported by nine studies [6
], illustrates another main focus of the current research regarding regular compulsory school- and curriculum-based outdoor education programmes.
According to the results in social dimensions, students seem to benefit in terms of their development of social competencies and social relations such as self-esteem, self-confidence, trusting relationships, and the sense of belonging [6
]. One study [23
] also reported that students mentioned perceived positive programmes effects, however, with a temporal shift of approximately eight months. Furthermore, three studies reported positive effects on students’ attitudes and behaviour patterns towards the environment [30
]. One study [28
] mentioned negative effects on students’ environmental attitudes. The methodological quality for studies reporting on social dimension is rated as moderate [6
] except for two studies rated as high [23
]. Despite the methodological weaknesses, the reported results are in concordance with conclusions by Waite, Bølling and Bentsen [1
]: Forest schools, as well as udeskole programmes, can promote students’ social relations, interpersonal skills, and social competencies. Furthermore, Rickinson et al. [2
] summarised that fieldwork and visits “can lead to individual growth and improvements in social skills (…) and improve attitudes towards the environment” while school grounds and community projects can foster students’ sense of belonging, relationships and community involvement.
Similar to our demands regarding learning dimensions, there is also a strong need for more high quality-studies to further examine possible effects of regular outdoor classes on students’ social dimensions.
4.5. Additional Dimensions
The research on students’ physical activity, mental health and action regulation behaviour is underrepresented in comparison to results on students’ learning and social dimensions. Only two case studies [4
] with moderate to low methodological quality, reported positive effects on students’ PA. Only one case study [33
] with moderate methodological quality mentioned gender differences with respect to action regulation behaviour. Furthermore, only one quasi-experimental study [5
], with a high methodological quality reported positive effects of regular outdoor classes on boys’ mental health. Therefore, the presented results of PA, mental health and action regulation behaviour can at most be interpreted as first indications. However, taking results from related publications into account, these indications can be partly supported. In detail, Rickinson et al. [2
] showed in their review that school grounds and community projects can be beneficial for children’s exercise. Additionally, Waite, Bølling and Bentsen [1
] mentioned that forest school and udeskole projects increased students’ PA and motor-skills. Regarding students’ mental health, Cason and Gillis [19
] found an average effect size of 1.047 (n
= 12; SD = 0.459) for adolescents’ clinical scales (e.g., depression and anxiety) regarding outdoor adventure programming.
More high quality-studies are therefore needed to further examine these first indications of the effects of regular outdoor classes on students’ PA, mental health and action regulation behaviour, especially when considering an increasing inactivity [39
], as well as a rising number of diagnosed mental health disorders in school children [40
4.6. Strengths and Limitations
There are four main strengths in this systematic review. First, we strictly referred to a search protocol and design according to the PRISMA Guidelines and applied several online databases for literature research. Secondly, the chosen inclusion criteria allowed for the consideration of a wide range of studies concerning study design, country, target group and reported outcomes. Thirdly, two reviewers independently screened the literature and assessed the methodological quality of the included studies and, fourthly, we applied the CCEERC Quantitative Research Assessment Tool as well as the JBI Checklist for Qualitative Research to rate the studies’ methodological quality.
However, we only evaluated studies published in English and German in peer-reviewed journals and listed in the used online databases, but no grey literature or reports. We therefore cannot rule out the existence of relevant studies in other languages or studies published elsewhere. Furthermore, we observed that several included, as well as excluded, articles were weak in respect of the internal structure and given information. Hypothesising that this is a wide spread practice, this could also mean that other valuable research results had not been properly published in peer-reviewed journals, and were therefore not eligible for inclusion in this systematic review.
These limitations are in concordance with the critique on systematic reviews in education, as described in the methods chapter. Therefore, we cannot claim to have delivered an all-embracing solution to the questions we have asked. We have not “eliminate(ed) bias” nor have we “present(ed) an ‘objective’ version of the truth, but” we have “attempt(ed) to minimise bias” in the field [41
To conclude, the number of identified studies on regular compulsory school- and curriculum-based outdoor education programmes is relatively low. In addition, these 13 evaluated studies show wide heterogeneity in respect of the aims, participant groups, learning environments, methods used and reported effects, and the methodological quality is, on average, moderate. However, tendencies were found which indicate that regular compulsory school- and curriculum-based outdoor education programmes can advance students in the physical, psychological, learning and social dimensions.
To further evaluate these indications, more research studies are needed. Thereby, a strong focus on aspects of study design and methodological quality has to be set. Especially randomised-controlled trials, longitudinal studies and studies that are more quasi-experimental with a higher number of participants are desirable for future research. Additionally, the intervention duration should be as long as possible, as it has been shown that longer programmes lead to better effects [2
]. Future research should particularly focus on aspects of students’ PA and mental health, as we have shown that those are underrepresented in the reviewed literature.
However, these study designs are often difficult to conduct in educational settings, especially as practical “Outdoor Education’ strongly depends on the respective teachers” motivation and beliefs, their pedagogical concepts and ideas, and a certain financial support from headmasters/headmistresses and school authorities [1
]. If practitioners, researchers and policymakers work more closely together in a dialogic relationship and with a strong focus on what is needed, as demanded by Fiennes et al. [20
] and Andrews [41
], positive changes in school practise can hopefully be realised for students’ benefits. This can partly be seen in relationship to a recent OECD report on learning environments in the 21st century. According to the report, innovative learning environments are needed. Specifically, a combination of pedagogical approaches on “guided learning”, “action learning” and “experiential learning” that enables self-regulated learning [42
]. Although not being the focus in our review, the underlying pedagogical concepts in outdoor education do set focus at least partially on these learning environments [1
One promising example is the Danish TEACHOUT research project which used a quasi-experimental and longitudinal design to analyse the impacts of regular outdoor teaching on 834 students’ PA, well-being, social interaction and learning [43
]. First results are to be expected in 2017. In the future, more such high-quality studies should be realised by referring to a rich theoretical background and methodology, as well as informing and including policy and school administration.