This chapter provides a review of the literature used to inform the small research project described in this report. To collect literature for my thesis, I accessed the websites for Zunia, ERIC, UNICEF, MoEYS, UNESCO, and the e-journal collection at James Cook University. There were difficulties in gaining access to some sources because many were password protected. Also a challenge was locating articles written for the Cambodian context, which has limited the scope of the literature review for the local Cambodian context. Furthermore, many of the articles I searched were secondary data sources, so it was sometimes difficult to cite or quote because some secondary sources did not provide detailed information. At times it was a description of a study written by someone other than the person who conducted it. I also had trouble in determining which articles were related directly to my topic to be included (Gay, Mills, & Airasian, 2009). Besides using various databases, I also read books about the student-centered theory and previous studies conducted by UNICEF (United Nation Children's Fund) as well the Cambodian-based project evaluation written by VVOB.
The key words used to locate literature were: student-centered, learner-centered, constructivism, social constructivism, the zone of proximal development, scaffolding, student-centered teaching, and student-centered classroom. The reference sections of relevant articles were also used for identifying other studies that would be relevant to this review.
The chapter has been structured following several themes that emerged as literature was reviewed. It will describe the relevant literature focused on the issues surrounding the research objective. This chapter has been classified into several sub sections based on the themes that emerged during reading.
2. 1 Constructivist Theory as the Framework for Student-Centered Strategies
Within the past two decades, the concept of "constructivism"Â has been drawing attention from educators (Airasian & Walsh, 1997). Since constructivist theory is an epistemology and philosophy and not a theory of learning, constructivist pedagogy has been developed by educators influenced by the ideas of knowledge construction found within constructivist theory (Yilmaz, 2008). "Constructivist pedagogy is informed by the ideas of John Dewey and William James; the latter work of Jean Piaget; and the sociohistorical work of Lew Vygotsky, Jerome Bruner, and Ernst von Glasersfeld" (p. 165).
According to Dewey, the relationship of the individual to his or her environment and the building of experience through action are very important. This importance has also been recognized by constructivism, especially social constructivism (Brush & Saye, 2000). Piaget's work dealt with the stages of development which people go through and the importance of discovery in learning (Alexander, 2006). Vygotsky's work focused on social interaction as an agent of learning as well as the importance of a student's existing experience and knowledge (Alexander, 2006; Yilmaz, 2008). Among constructivism's three foundational scholars, Dewey, Piaget, and Vygotsky, Vygotsky's work has had a clear influence on the concept of social constructivism and played an important role in modern constructivist thought because two of his four key principles are; collaborative learning and student-centeredness (Yilmaz, 2008). His first key concept focuses on the social nature of learning hence the term 'social constructivism' and the second is that children learn best the concepts that are within their zone of proximal development (ZPD).
The ZPD is a concept used to describe how a child's learning and child's cognitive development levels develop together in social situations (Vygotsky, 1978). The ZPD is considered among the most useful both theoretically and practically; of all the concepts that are created by Vygotsky (Chenyne & Tarulli, 1999). The concept of ZPD, which focuses on the relation between human learning and development, is the second foundation for scaffolding classroom instruction (Stuyf, 2002). The ZPD is defined as "the distance between the actual developmental level as determined by independent problem solving and the level of potential development as determined through problem solving under adult guidance or in collaboration with more capable peers" (Vygotsky, 1978, p. 86). Alexander (2006), Shear (2007), and Stuyf (2002) describe the ZPD as the area between what a learner can accomplish mentally and do independently by themselves, and what the learner can accomplish with the help or the support of a more knowledgeable other adult or peer. The peer shares knowledge with the learner to build the gap between what is known and what is not known (Shear, 2007).
The concept of ZPD is now widely applied in teaching and learning in many subject-matter areas (Willis, 1996). The idea of the ZPD informs teacher scaffolding of learning to create effective learning environments. It means effective learning takes place within the child's ZPD. Vygotsky stated that:Â
Learning awakens a variety of internal developmental processes that are able to operate only when the child is interacting with people in his environment and in cooperation with his peers. When these processes are internalized, they become part of the child's independent developmental achievement. (Vygotsky, 1978, p. 90).
Similarly, Wilhelm, Baker & Dube (2001) argued that the ZPD is the cognitive area in which effective instruction and learning can happen. Teacher, peers, and instructional environment are the assistance and support which students can learn with and this lies within the ZPD. "A child's new capacities can only be developed in the ZPD through collaboration in actual, concrete, situated activities with an adult or more capable peer" (Wilhelm, Baker & Dube, 2001, p. 3)
For constructivist oriented teachers, the importance of designing an instructional activity is to identify a problem and provide students with resources to help to solve the problems thereby providing opportunities for students to view problems from a variety of perspectives, allowing students to collaborate and negotiate solutions to problems and test those solutions in a real world context (Bednar et al, Duffy & Jonassen, Brown, Collins & Duguid as cited in Brush & Saye, 2000). Similarly according to UNESCO (as cited in Mtika & Gates, 2010), student-centered education helps to prepare students to meet society's expectations, to design educational experiences to advance students' learning, and provide opportunities for students to demonstrate their success in achieving societal expectations.
2. 2 What is Constructivism?
Constructivism is not a theory about teaching, but it is a theory about knowledge and learning (Haney & McArthur, 2001). According to Airasian & Walsh (1997), constructivism is not an instructional approach; it is a theory about how learners come to know or how people learn. Brady (2006) & Staver (1997) stated that constructivism comes from traditional epistemology, which offers a philosophical explanation about the nature of knowledge. Constructivists believe that knowledge is created from the interaction between existing experiences or knowledge of people and new ideas or situations they encounter.
In the constructivist classroom, learners are encouraged to make connections between their existing knowledge and new experience; this is the process of constructing knowledge (Airasian & Walsh, 1997). Furthermore, over the last decade, constructivism has significantly influenced science educators because it links students' existing ideas to new experience and new information (Haney & McArthur, 2001; Staver, 1997; Yilmaz, 2008). Similarly, Driver, Asoko, Leach, Mortimer, and Scott (as cited in Hand et al., 1997) stated that social constructivist approaches in science education are not new. The implementation of constructivist learning theory has helped to develop the interaction between students and teacher and provide opportunities to construct science knowledge in the classroom. Similarly, Mtika and Gates (2010) argued that this pedagogical theory helps to encourage students' interaction with the subject's contents and with one another while the teacher facilitates the learning process.
Constructivism has been divided by some theorists into three categories (Alexander, 2006; Yilmaz, 2008). They are Cognitive constructivism, Radical constructivism, and Social constructivism. These three categories emphasize that knowledge and meaning are constructed by the human mind (Yilmaz, 2008), however there are distinctions between them (Hirumi, 2002). Cognitive constructivism focuses on individual's interactions with the environment. Radical constructivism emphasizes the individual's knowledge construction which is based on previous knowledge and experiences, and social constructivism concentrates on individuals within groups and their sociocultural contexts (Alexander, 2006; Yilmaz, 2008).
Though constructivism has been categorized into three, according to Staver (1997), the two most comprehensive and famous categories of constructivism are radical and social constructivism. The two brands have much in common. First, knowledge is created by the thinking of a person and a community. Second, social interactions between and among learners are central to building knowledge. Knowledge is built by individuals within their communities, societies, and cultures. Furthermore, the means of social interaction is primarily language because language is a way that humans communicate and understand each other. Third, the character of cognition is functional and adaptive, that it is in an active process (Staver, 1997; Yilmaz, 2008). Finally, the purpose of cognition is to serve the individuals' organization of his or her experiential world. However, the two brands are primarily different. Radical constructivism focuses on cognition and the individual, whereas social constructivism focuses on language and the group.
2. 3 Constructivism in the Classroom
Airasian & Walsh (1997) argued that constructivism is accepted in many education systems because it helps to promote higher order thinking skills of students. Similarly, according to the study of Hand et al., (1997), involvement of students' ideas or thinking is the most important factor that influences students' learning. In the study of a group of junior secondary college students in Australia, students reported that they enjoyed learning through small group work, class discussion, developing their own ideas, less note taking, and they developed a greater understanding of concepts. These are all learning strategies that reflect the use of social constructivism in the formal learning context. Among the categories of constructivism, social constructivism approaches are useful for students because students can be required to work in a group or individually and do not need to wait for a teacher to direct their learning. "The vision of the constructivist student is one of activity, involvement, creativity, and the building of personal knowledge and understanding" (Airasian & Walsh, 1997, p. 446).
Whether social constructivists emphasize cognitive development or social interactions, there are several specific things that teachers can do to help learners to construct their understanding, structural scaffolding is one of these things (Killen, 2003). Literally, scaffolding is a structural support that is set up around a building under construction. In education in a metaphorical sense, scaffoldings are the support structures that are provided by others such as parents, peers, and teachers to students to enable them to complete a task and experience achievement in their learning (Yang & Wilson, 2006). According to Hammond & Gibbons (as cited in Yang & Wilson, 2006), effective scaffolding is both high challenge and high support. "Vygotsky stressed that students need to engage in challenging tasks that they can successfully complete with appropriate help" (Wilhelm, Baker, & Dube, 2001, p. 4).
Scaffolding is a process whereby a teacher or peer gives aid or support to the students in their ZPD as it is necessary and removes this aid when unnecessary (Killen, 2003). "Scaffolding must begin from what is near to the students' experience and build to what is further from their experience" (Wilhelm, Baker, & Dube, 2001, p. 4). Similarly, at the beginning of a new learning task, the scaffolding should be prepare to be concrete, visible, and external, so learning can begin from the concrete to the abstract.
The concept of scaffolding is closely related to the ZPD because scaffolding was developed by other socio-cultural theorists applying Vygotsky's concept of ZPD to educational contexts (Yang & Wilson, 2006). In other words, the idea of scaffolding originally came from Vygotsky's socio-cultural theory (Stuyf, 2002).
Mitchell and Myles (as cited in Yang & Wilson, 2006) stated that social constructivism focuses on learning that occurs in socio-cultural environments and learners become active constructors of their own learning environment. Vygotsky's socio-cultural theory proposes that social interaction plays a fundamental role in the development of cognition. Learners are not therefore isolated individuals; they are active learners because of social interactions (Stuyf, 2002; Yang & Wilson, 2006).