key: cord-333806-e3v67hpx authors: Ardoin, Nicole M.; Bowers, Alison W. title: Early childhood environmental education: A systematic review of the research literature date: 2020-07-10 journal: nan DOI: 10.1016/j.edurev.2020.100353 sha: doc_id: 333806 cord_uid: e3v67hpx Abstract Environmental education focused on the early-childhood years is experiencing dynamic growth in research and practice due to persistent environmental challenges coupled with burgeoning interest in the documented benefits of nature-rich experiences for infants and children. To better understand the landscape of early childhood environmental education (ECEE) pedagogical practices and expected outcomes, we undertook a systematic review of empirical studies of ECEE programs. Focusing on a 25-year span, we surfaced 66 studies that met our inclusion criteria. We found that participants in such programs spanned the early-childhood age range (birth through age eight) with the majority involving three-to six-year-olds in teacher-led, formal (school-like) programs. The primary outcomes documented in our sample studies included environmental literacy development, cognitive development, and social and emotional development. To a lesser extent, the studies addressed physical development and language and literacy development. On balance, our sample of ECEE studies reported strongly positive findings associated with the aforementioned outcomes. The majority emphasized the effectiveness of play-based, nature-rich pedagogical approaches that incorporated movement and social interaction. We include a visualization that synthesizes cross-sample findings with the intention of assisting ECEE practitioners in developing, implementing, and evaluating programs as well as encouraging researchers to further study elements, processes, and theoretical assumptions inherent in them. Environmental conditions across the globe continue to deteriorate at an alarming pace 27 due to a complex web of social-ecological challenges including, but not limited to, climate 28 change, air and water pollution, ocean acidification, land degradation, and biodiversity loss 29 (Barnosky & Hadly, 2016) . Scientists focused on these declining planetary conditions emphasize 30 the importance of healthy, functioning, and resilient ecosystems as essential to all living beings, 31 including humans (UN Environment, 2019). Many note that protecting and restoring the global 32 environment will require transformative changes in human production and consumption-related Operator Environmental education search terms (childcare OR "day care*" OR "early childhood" OR "early elementary" OR "early primary" OR infants OR kindergarten OR "nursery school*" OR preschool* OR "primary grade*" OR toddler* OR "young child" OR "young children" AND ("conservation education" OR "education for sustainability" OR "education for sustainable development" OR "environmental education" OR "forest kindergarten*" OR "forest school*" OR gardening OR "nature preschool*" OR "nature-based preschool*" OR "outdoor classroom*"OR "school garden*" OR "sustainability education") Note. The asterisk "*" is a truncation symbol, which directs the search engine to find all forms of a given word. The 163 term forest school*, for example, returns results containing "forest school" or "forest schools." of key journals that regularly publish ECEE research. Finding that the database searches did not 172 consistently return results from two journals, International Journal of Early Childhood 173 Environmental Education and Children, Youth and Environments, we conducted manual table-174 of-contents reviews for those two journals. Through the manual search process, we added 529 175 citation records and removed 25 duplicates, leaving a total of 504 unique citation records 176 identified via manual searches of the two journals. The combined results from both search 177 strategies (database and manual journal searching) yielded 1,629 total citation records. 178 To screen the 1,629 citation records, at least two research team members read each 180 abstract and used a decision tree to identify relevant studies based on the following inclusion 181 criteria: 182 • Focused on early childhood/young children, birth through age eight and/or 183 through third grade within the U.S. educational system; 184 • Reported on an environmental education experience and/or program. Throughout 185 the review, we included sustainability and conservation education as nearly 186 synonymous with environmental education; we also were broad in our definitions 187 around early childhood-specific terms, such as nature preschools and forest 188 schools; and 189 • Designed as empirical research or evaluation. This criterion was designed to 190 exclude other reviews as well as long-form discussion pieces focused primarily on 191 theoretical perspectives. 192 During the first review round, we excluded articles in practitioner-oriented journals, 193 which resulted in eliminating articles intended for classroom teachers, that described classroom 194 activities, or that included detailed lesson plans. We also excluded dissertations, textbooks, and 195 conference presentations unavailable as published resources. 1 Based on reviewing the abstracts, 196 we excluded 1,371 citation records, many of which involved children outside of the designated 197 age range, focused on educators rather than children, and/or did not meet other review criteria. 198 We then located the full-text versions for the remaining 258 citations. Next, we focused on 199 eligibility for final inclusion in the review. At least two team members reviewed the full text of 200 those 258 records to confirm that the articles met the previously described first-round inclusion 201 criteria. After reviewing full-text versions of the 258 citation records, we excluded 188 for 202 failing to meet the initial inclusion criteria. 203 We devised and applied a generic framework (i.e., we did not apply different quality 205 criteria for quantitative, qualitative, or mixed-methods studies), which relied on expert 206 judgement and a set of predefined quality criteria. This quality-appraisal approach was informed 207 by several review factors: The search process identified studies with varied research designs (i.e., 208 qualitative, quantitative, and mixed-methods approaches). We employed an expert panel to 209 provide external feedback throughout the process; our review team included research 210 methodologists and members with prior experience conducting systematic reviews. Our 211 predefined quality criteria included ensuring that studies provided relevant program descriptions; 212 basic information about research methods and data; and sufficiently detailed findings. We 213 selected these criteria as our review was designed to be configurative, rather than aggregative, 214 focusing on identifying common practices and outcomes in ECEE. 2 Additionally, although we 215 recognize that the peer-review process is at times inconsistent, we chose to include only peer-216 reviewed studies in our final sample, as that process suggests that some level of quality appraisal 217 had been conducted. 218 Using a decision-tree process similar to that of the screening-and-eligibility process 219 described above, at least two research team members reviewed each of the 70 studies, addressing 220 quality-related elements; in this manner, all studies were assessed at least twice (National 221 Institute for Health and Clinical Excellence, 2012). In addition to asking each reviewer for an 222 overall impression of study quality, we applied two study-quality-related eligibility criteria. 223 Specifically, we sought studies that: (1) sufficiently described research methods and measures as 224 well as data-collection tools/instruments, and (2) presented clear-cut data to support claims. The 225 research team met to discuss opinions and evaluation of quality for each study and ensure 226 consistent application of the quality criteria. During the quality review, team members agreed on 227 four studies that did not meet the quality criteria. The final sample included 66 studies (65 peer-228 reviewed articles and 1 peer-reviewed conference paper). 229 The 66 studies in our final sample represented a variety of research designs that produced 231 qualitative and quantitative data; thus, we employed a mixed research synthesis review approach 232 Table 2 ). When 235 possible, we used in vivo coding, extracting exact wording, leading to the development of new 236 codes (Saldaña, 2016) . This inductive technique did not limit coders to predetermined codes and 237 facilitated capturing unexpected data (Charmaz, 2014 Team members pilot-tested the codebook, resolved discrepancies through group 243 discussion, and reached 100% agreement on coding decisions before proceeding to fully code the 244 comprehensive set of studies. To do so, we used an iterative process, facilitated through NVivo 245 12 (a qualitative data analysis software), modifying the codebook based on emergent trends. We 246 added, revised, and rearranged codes until reaching a saturation point (i.e., no new codes were 247 generated). In initial rounds of coding, for example, we assigned codes to describe the program 248 setting, such as a preschool or local park. In subsequent rounds, we noticed patterns related to 249 whether the setting included an outdoor component; we therefore revised the setting category to 250 note inclusion of an outdoor component. 251 Where appropriate, we used counting to aggregate the data, which allowed us to identify 252 trends in the data (Miles et al., 2014) . With publication year, for example, we coded and counted 253 the data categories by year (e.g., 2000, 2001, and so on), using a combination of NVivo and 254 Excel to manage the process across the dataset. We also used counting for publication outlet, 255 research type, country, participant age(s), facilitator, program length, program travel, program 256 setting, and overall findings. Those data provided a general description of the programs included 257 in the final sample. 258 To analyze data in the remaining categories of outcomes and practices, we used a 259 modified grounded theory approach (Corbin & Strauss, 2015) to identify core categories. In 260 initial coding rounds, we identified all reported outcomes and practices. As coding progressed, 261 we grouped outcomes and practices into broader categories. For coding outcomes, we used a 262 We coded 36 of the studies (55%) as primarily focusing on qualitative data; 17 (26%) on 303 quantitative data; and 13 (11%) used mixed-methods approaches to produce both qualitative and 304 quantitative data. With regard to valence of overall findings, we coded 54 studies (82%) as 305 reporting mainly positive findings, 11 (17%) as reporting a mix of positive and null findings, and 306 1 (2%) as reporting only null findings (i.e., no change in the measured outcomes). We did not 307 code any studies as reporting mainly negative findings. 308 The 66 studies in our sample involved programs whose participants spanned the early 310 childhood age range. Although the distribution across studies approximated a normal curve, the 311 most common age of focus was four-and five-year-olds. To the extent possible, we extracted data about program setting, such as whether the 336 program occurred as part of a school or daycare experience (formal setting) or related to a 337 museum, park, or visit, not otherwise included in a structured school/daycare experience 338 (nonformal setting). The majority of studies (62, 94%) examined a formal ECEE program that 339 occurred onsite at a school, daycare, or early childhood education center; only five studies (8%) 340 described programs occurring in a nonformal setting. 341 We considered whether programs under study involved the children spending time 342 outside and/or in nature-rich settings. Of the 66 studies, the majority (54, 83%) examined 343 programs that included time outside in a natural environment, a nature-rich setting, or an 344 environment with a preponderance of nature-inspired features. Eleven of the studies (17%) 345 described primarily indoor programs. 346 We developed five broad coding categories for participant outcomes based on NAEYC 348 (Copple & Bredekamp, 2009) Table 3 ). In the articles we 351 reviewed, the most frequently reported outcomes were related to the category of Environmental During the initial coding process, we found that researchers described evidence of more 371 than 150 pedagogical practices associated with effective ECEE programs among the 66 studies. 372 Researcher-described effective pedagogical practices included a range of engagement types and 373 settings from highly active and immersive (e.g., hiking outdoors), to reflective (e.g., creating 374 drawings), to analytical and synthetic (e.g., guided in-class discussions). We organized the 150 375 coded practices into nine thematic codes that described ECEE strategies supporting development 376 Observe; Action Taking; Family Connection; and Personal Connection (see Table 4 ). 379 The most frequently studied ECEE programs involved children in the four-and five-year-453 old age ranges participating in ongoing, educator-facilitated programs that included time in 454 nature-rich settings and occurred in a formal setting, such as a school, daycare, or early 455 childhood center. Although this general picture emerged, diversity existed in our sample 456 suggesting ECEE variations that may be in need of additional study; we highlight those areas 457 below. 458 Examining the data concerning participant age revealed a close-to-normal distribution 459 with children ages four and five being the most frequently studied age group (see Fig. 3 ). In 460 many countries, children in this age group are attending school for the first time, either as part of 461 a preschool or kindergarten experience, or as part of their first year in primary school. Given the 462 importance of this age as many children are transitioning into formal schooling, it is not 463 surprising that this is a well-studied age group; however, early childhood's early (birth through 464 age two) and later (ages seven through eight) years represent areas in need of further EE-focused 465 research. The infant and toddler stages (birth through age two) can be difficult to study using 466 traditional research approaches because of a lack of language skills as well as their still-nascent, 467 yet developing, psychomotor abilities. Taken together, these can greatly limit programmatic 468 outcomes as well as measurement approaches. This age, however, also represents a foundational 91% of the 119 studies reported environmental outcomes and only 34% included non-507 environmental outcomes (Ardoin et al., 2018) . These data suggest that either (1) researchers 508 focusing on ECEE programs are more likely to address and focus on non-environmentally 509 related outcomes than their K-12 counterparts; or (2) ECEE programs, overall, are more likely to 510 pursue alternative, non-environmentally related outcomes. One explanation, in light of the 511 growing body of evidence demonstrating the social and physiological benefits of time in nature-512 rich environments, is that ECEE programs are leveraging critical early-childhood developmental 513 stages and processes related to cognition, physical health, wellbeing, moral development, social 514 Concurrently, it is essential to assist key stakeholders, such as policymakers and 567 supervisors, and influential implementers, such as educators, in understanding and embracing the 568 complex influence of a range of nature-rich settings on young people. As Adams and Savahl 569 (2017) noted, not all children and educators have equal access to safe, clean nature-rich areas 570 that provide opportunities for enriching educational experiences. In certain places, simply "going 571 outside" or finding a proximal nature-rich context may be difficult, or may not create a platform 572 for a universally positive experience. To address such challenges, daycare center staff in 573 Australia, for example, worked with researchers to develop an arts program drawing on nature-574 inspired themes and incorporating natural materials into ongoing activities to provide children 575 with consistent nature exposure, even when outdoor space was lacking (Tarr, 2008) . In these 576 ways and others, the role played by nature and nature-rich experiences can be enhanced even 577 when teaching and learning indoors, or with limited access to nature. Early in the review process, we necessarily defined our research questions tightly and 599 constrained our search, resulting in a narrowing of the study's scope to focus on outcomes 600 associated with birth through age eight. Yet environmental education outcomes can, and often 601 do, reach an audience far beyond the participants. In our studies, for example, we encountered 602 measured outcomes specific to the early childhood educators, families of the young children, and 603 the educational institutions. As those audiences were beyond this review's scope, we did not 604 code for those outcomes, but we recognize that they, too, are important and worthy of future 605 study. 606 We also note geographical limitations in this study and analysis: Our review sample did 607 not include studies from Latin America and Africa, as our systematic approach did not uncover 608 studies in those areas that met our criteria (i.e., empirical, participant outcomes, published in 609 English). We necessarily limited our search to English-language studies as a practical 610 consideration based, first, on readily available articles and papers, and second, the research 611 team's linguistic competency. This delimitation certainly caused us to miss relevant research, 612 and the lack of studies from areas such as Central and South America may reflect a structural 613 barrier (e.g., linguistics), rather than the amount of research (or lack thereof) conducted in those 614 areas. 615 Latin America and considers journal articles published in both English and Spanish. Their 618 review, however, does not separate the reviewed articles by language or geographic location; 619 thus, the details provided are not granular enough to include in our sample. Alternatively, our 620 study sample represents regions where ECEE is a more frequent practice due to a variety of 621 factors. Regardless of the particular reasons for which studies from Latin America and Africa did 622 not surface in our review, the implication is that more ECEE research in Latin America and 623 Africa should be encouraged and shared in a wider venue, thus developing a comprehensive 624 understanding of ECEE research across such settings and worldwide. 625 Our discussion of the findings surfaced several additional areas requiring future research. 626 More research is needed with very young children (birth through age two), as this is an 627 underrepresented age group in our sample. Similarly, additional research with children at the 628 opposite end of the early childhood range (ages seven through eight) shows a dearth. 629 We also highlighted a need for ECEE research into programs that occur in less-630 structured, nonformal learning environments. Moreover, we note a particularly vibrant 631 opportunity for enhanced early childhood environmental learning in the course of everyday life, 632 mediated by familial or caregiver-child interactions. Our search process uncovered few such 633 studies, although this may have been a reflection of our search terms: many researchers and 634 practitioners do not envision caregiver-child or familial interactions in the outdoors or nature-635 rich settings as examples of "environmental learning," per se, regardless of content or skills 636 developed. Yet perhaps these socioculturally embedded interactions-reimagined to more richly 637 contextualize, mark, and connect environmental learning with relevant daily-life activities-638 could become a consistent, more commonly recognized and studied aspect of the ECEE 639 ecosystem (Jarvis, 2009 ; BLINDED FOR REVIEW). 640 Our review suggests that ECEE encourages young children affectively, in terms of 642 exploring the environment, bolstering their sense of self-confidence, and making social 643 connections with each other; developing cognitive frameworks for understanding the natural 644 world; and laying the groundwork for skills and dispositions related to taking action to improve 645 and protect the environment. Our review sample studies describe programs focusing on trees, 646 water, and nature more generally; many take place in immersive, nature-rich settings, while 647 others bring nature-rich elements into classrooms. The programs include a range of outcomes 648 designed to nurture children's development of action skills and encourage developmentally 649 appropriate pro-environmental behaviors. In addition to an environmental focus, the reviewed 650 studies indicate that ECEE programs emphasize related early childhood goals of personal 651 development as well as academic progress (e.g., in the form of kindergarten readiness). 652 Our sampled studies provide evidence of strongly positive outcomes from ECEE, when 653 measured holistically across a range of affective and cognitive dimensions, conveying how those 654 programs often engender a sense of joy and curiosity inherent in effective early childhood 655 educational programs. The programs encourage young participants to connect those affective 656 elements with environmentally related knowledge, action orientation, and civic engagement, 657 focused on the environment not only as an educational setting, but in its totality (Sauvé, 2005) . 658 As Bailie (2012) writes, "the combination of early childhood education and environmental 659 education is more powerful together than each by itself" (p. 132). Such a synergistic relationship 660 offers promise to enhance the quality of the human experience in the world with beneficial 661 impacts for spaces and species, for generations to come. 662 6. 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Thanks also to numerous Stanford Social Ecology Lab members who provided research assistance, especially: Estelle Gaillard, Avery Hanna, Tucker Hirsch, Wendi Hoover, Marika Jaeger, Fiona Noonan, Alexandra Peers, and Indira Phukan.