In recent years, researchers and policy makers around the world have increasingly called for greater attention to be paid to the educational potential of out-of-school settings, citing the many benefits and the necessity of learning in contexts other than the classroom. For example, the Manifesto for Learning Outside the Classroom (LOtC) introduced by the British government encourages schools to provide children with learning opportunities beyond the classroom (Department for Education and Skills, 2006). Moreover, the new principles for curriculum design outlined in the Big Picture credits outdoor learning with being one of the key components for building a valid curriculum (Qualifications and Curriculum Authority, 2008). Outdoor learning experiences have positive influence on pupils' classroom learning as recent research indicates that school trips to informal settings such as science museums, botanic gardens and zoos are valuable in developing pupils' understanding of and interest in science (Braund & Reiss, 2004; Malone, 2008; Ofsted, 2008; Rickinson, et al., 2004; Slingsby, 2006).
Public gardens, parks and botanic gardens attract a large number of international and domestic visitors throughout the world. According to the statistics of the Botanic Gardens Conservation International (BGCI), there are over 2,000 botanic gardens in the world with around 250 million visitors each year. In the United Kingdom, there are approximately 16 million visits to local gardens that are open to the public each year (Connell, 2004) and a large proportion of these visitors are schoolchildren (Sanders, 2004). As one of the most popular places for young people, botanic gardens enable them to acquire practical biological knowledge and horticulture skills, learn to appreciate the natural environment, foster environmental awareness and sense of sustainability (Willison, 2006). In other words, botanic gardens play a significant role in providing the public with an enjoyable way to spend leisure time and the opportunity to explore the pleasures of the garden environment whilst also serving as a site for enhancing public education (Johnson, 2004; Sanders, 2007; Stewart, 2003; Tunnicliffe, 2001). For instance, the Royal Botanic Gardens at Kew, a leading institute in promoting school education programmes in England, states that the aims of their school education programmes are to inspire and deliver science-based plant conservation worldwide, so as to enhance g the quality of life (RBG Kew, 2009).
Botanic gardens provide some of the most popular settings for school trips. In England, school trips guided by botanic garden educators (BGE, hereafter) have become one of the most important components of botanic garden education (Botanic Garden Education Network, 2009). Unlike schoolteachers, who may lack confidence in teaching beyond the classroom (Nundy, Dillon, & Dowd, 2009; O'Donnell, Morris, & Wilson, 2006), these BGEs are experienced in delivering outdoor learning activities to different age groups of children (Bowker, 2002). Although the BGEs' lessons are usually one-offs and last only a short period of time, the pupils can still learn more by participating in these than during schoolteacher-led visits (Bowker, 2002; Bowker & Jasper, 2007). In particular, they effectively offer pupils an environment that supports inspirational learning about plants and their importance as BGEs serve as the communicators of knowledge regarding biological science and plant conservation to the garden visitors. With respect to school groups, these educators help children to connect their normal daily life experiences to the knowledge about the plants on display in botanic gardens (Bowker & Jasper, 2007; Sanders, 2004). In addition, previous research on education carried out in botanic gardens has suggested that the BGEs fulfill a variety of roles, such as those of "professional educator, tour guide, and a source of information" (Stewart, 2003, p. 354).
Learning in botanic gardens is considered to constitute more than learning school science, although visits by children in school groups are often dominated by exploring school subject matter, with the content usually being connected to the National Curriculum (Jones, 2000). As such, often there are few opportunities to obtain extra-curricular ecological knowledge and horticultural skills. If the purpose of the BGEs is to include these extra activities in their deliver, it is important to explore whether and how they endeavour to achieve this objective. Moreover, although there are increasing numbers of studies on learning in informal contexts, to date, botanic gardens as sites of learning have largely been ignored by scholars. For example, in Rickinson et al.'s (2001) review of outdoor learning, the authors overlooked the opportunity to consider the work missed that has carried out regarding botanic gardens. In fact, limited research in this domain has been published in the relevant environmental education and science education research journals and consequently. I discovered that most of the related literature was made available from the Botanic Gardens Conservation International (BGCI) conferences or the official websites of botanic gardens. Further, on searching the databases that list master and doctoral thesis abstracts, a scant number of entries related to teaching and learning in botanic gardens are available.
Ohlsson (1996) argued that learning to understand abstract knowledge, such as concepts, ideas and principles, requires learners to take part in a list of epistemic tasks, including: describing, explaining, predicting, arguing, critiquing, explicating and defining. That is, he pertained that it is essential for learners to be socially and intellectually engaged, if effective learning is to take place. In the same vein, according to Newmann et al. (1992), engagement is the doorway towards learning, understanding, and the mastering of knowledge and skills. Notwithstanding the above, abundant research has shown that young people can benefit greatly from their experiences of learning outside of the classroom (Kahn & Kellert, 2002; Nundy, 1999; Rickinson, et al., 2004 for a review; South, 1999). However, little is known regarding whether they are actually engaged in learning during their educational visits to these informal settings and further, how the educators engage them with the different activities available in these settings (DeWitt, 2007; J. Dillon, et al., 2005).
Gombert (1992) argued that "the acquisition and restructuring of knowledge generally requires the conscious participation of the subject" (p. 195). In this regard, the conscious participation of the subject is the state of engagement in social activities, which is regarded as the final stage of knowledge construction in the individual's mind (Valsiner, 1997; Valsiner & Van Der Veer, 2000; van Lier, 1996; Vygotsky, 1978). In his summary of children's development, Vygotsky (1986) proposed that "any function in the child's cultural development appears twice, or on two planes; first it appears on the social plane, and then on the psychological plane" (p. 163). That is, a child acquires learning, first, through social interaction and this engagement provides the link to the psychological level, where the knowledge is internalised. Consequently, there is the need for education researchers to understand learning engagement, especially the strategies to engage people. Given that a number of scholars (for example, Alexander, 2006; J. S. Brown, Collins, & Duguid, 1989; Greeno, Collins, & Resnick, 1996; Greeno & The Middle School Mathematics Through Applications Project Group, 1998; Mercer & Littleton, 2007; Mortimer & Scott, 2003; Ohlsson, 1996; Osborne, Erduran, & Simmon, 2004; Rogoff, 1998; van Lier, 1996; Vosniadou, 2001; Vygotsky, 1986) have contended that learning starts from social interaction and that language should be considered as the most important tool for learning, then it follows that this language forms one of the most significant resources for engaging learners in the process of knowledge construction. With respect to science education, Lemke (1990) argued that learning science involves learning to talk science through classroom discourse and terms this "doing science through the medium of language" (p. xi). Furthermore, Mortimer and Scott (2003) have explained that "different kinds of interactions between teacher and pupils in science classroom contribute to meaning making and learning" (p. backcover).
According to previous studies carried out in science classrooms, one of the most efficient approaches for engaging children in making meaning out of scientific views is through talk (for example, Duschl & Osborne, 2002; Lemke, 1990; P. Scott, E. Mortimer, & O. G. Aguiar, 2006; Scott & Ametller, 2007) and the same claim has been made with regards to in informal settings (for example, DeWitt, 2007; Rahm, 1998; S. M. Rowe, 2002; Tunnicliffe, 2001). More specifically, according to Bruner (1996), young people need to think for themselves before they achieve conceptual understanding and teaching should provide them with those linguistic opportunities and encounters which will enable them to achieve this. Building on this, in Towards Dialogic Teaching: Rethinking Classroom Talk, Alexander (2006, p. 10) proposed the question "Do we provide and promote the right kind of talk?" to guide classroom teachers to reflect on their teaching. Other researchers (for example, Cazden, 2001; Edwards & Westgate, 1994) have pointed out owing to it being an important pedagogical component, more concentration than hitherto should be paid to teachers', especially in relation how they engage their pupils in discourse. Moreover, DeWitt (2007) has called for future research on learning in informal contexts to focus on the nature of spoken practitioner exchange with pupils during the visit.
Overview of the research
In light of the existing literature that states that the educator plays a critical role in determining the success of a school trip as a learning experience (for example, D. Anderson, Kisiel, & Storksdieck, 2006; Cox-Petersen, Marsh, Kisiel, & Melber, 2003; Griffin & Symington, 1997; Tal & Morag, 2007), the aim of this study is to explore this role in supporting and enriching such a learning experience. In seeking to characterise the pedagogical practices of the BGEs, three questions are proposed to guide the investigation of this thesis:
What is the structure of the BGE guided school visits?
How do the BGEs interact with pupils in terms of engaging and supporting learning?
What kind of pedagogical behaviours that facilitate pupils' learning can be observed during the guided visits?
In order to respond to these questions, a naturalistic case study enquiry is conducted, with the BGEs' practices in supporting and enriching children's visiting experiences being examined in detail. Data, including audio/video recordings of BGEs and pupils engaged in talk during the visits, field notes, interviews and pupil surveys, were collected for this study. The interviews with the BGEs identified their views of teaching and learning in botanic gardens and reflected their teaching practices as observed for this study. The investigation of the discourse between BGEs and pupils offered insight into the teaching and learning processes occurring in botanic gardens settings which reveals the quality of the pedagogical practices. Finally, to triangulate with the observation data, pupils' visiting experiences were researched through applying a post-visit survey.
Significance of the thesis
Much the strength of this thesis lies in the production of an in-depth, contextual understanding of BGEs' pedagogical thinking and choices that engage and support visiting schoolchildren's learning of ecological science. This thesis bridges the gap in the literature regarding science education in informal contexts. More specifically, by placing an emphasis on the pedagogical behaviours of BGEs this study seeks to develop a detailed understanding of the role of mediators in botanic gardens. The methodological considerations and analytical frameworks discussed in chapter 4 offer suggestions to other researchers who intend to investigate teaching and learning in similar settings, for example obtaining access to participants, data collection strategies and the development of analytical schemes. In practical terms, the findings from this thesis have implications regarding the further improvement of BGEs' teaching, the design of education programmes and professional development schemes. In addition, a contribution is made in the form of a framework for the development of pedagogical theory relating to outdoor settings.
Structure of the thesis
The outline of this thesis is set out in chapter 1. It begins with a review of the literature on teaching and learning in informal settings, highlighting the fact that there is little known about school trips in botanic gardens led by BGEs. Consequently, there is an emergent need to understand how the BGEs' practice impact upon visiting schoolchildren's learning experiences. In order to address this, three research questions are proposed which serve to guide this research. The practical, methodological and theoretical contributions of the thesis are presented.
Through a historical review of the development of botanic garden, in chapter 2 an overview of the development of botanic gardens as a teaching and learning environment is provided. In light of there being little extant research on school trips to botanic gardens, studies conducted in other informal contexts regarding the potential learning to be obtained from school trip experiences are reviewed so as to identify some insightful implications for this study.
The pedagogy that has the greatest potential to enrich pupils' scientific enquiry is discussed in chapter 3. By adopting the sociocultural perspective of learning, which emphasises the role of interaction for meaning making, this chapter reviews the mediating role of language in teaching and learning processes in both formal and informal contexts.
In chapter 4 the methodological choice for this study is explained. Following a discussion of the relevant epistemological assumptions, the interpretivist paradigm is selected as the most appropriate approach for guiding this investigation and the research procedures such as data collection and data analysis are described. Reflections on the methodology employed are given and issues regarding ethics, limitations, and trustworthiness are discussed.
The data gathered from the four participating BGEs including that from interviews, field observations and questionnaires are interwoven in order to draw up a holistic picture of each case which is subsequently presented in chapter 5. Moreover, the pedagogical thinking of the BGEs, the structure of the guided visits, and the nature of BGE-pupil interaction are discussed in this chapter.
In chapter 6 the data collected from the four cases are synthesised and a framework for analysing the pedagogical behaviours of the BGEs is developed. This framework includes the teaching behaviours of class management, pedagogical moves and teaching narratives. The term pedagogical move, used throughout this thesis refers to the non verbal physical gesture or body language that contains educational elements.
Finally, the conclusions of the findings which emerged from the four case studies and the synthesis of the BGEs' pedagogical behaviours are presented in chapter 7. Implications of this study for the future development of botanic garden education are considered along with the potential contributions of the thesis not only regarding teaching and learning in botanic garden settings, but also for application in other settings which present similar conditions to teachers and educators.