Constructivism is interested in how one constructs his knowledge from his experiences, beliefs and mental structures which are used to interpret objects and events. According to constructivist view there is no single reality and our world is created by our mind by interpreting events, objects, and perspectives on the real world. And our interpretations are personal. So we conceive of the external world based on our individual experiences. From a constructivist perspective, evaluating how learners construct knowledge is more important than resulting product (Duffy& Jonassen, 1992). So when students are acquiring knowledge, both student and teachers may evaluate how the students are progressing. As a result of this process, the importance of metacognition that is awareness of one own cognitive processeses or strategies appears. Metacognition refers knowledge about one's thinking includes awareness of one's own capacities, limitations and awareness of difficulties when they appear during learning. According to Brown (1978), metacognition has two components: knowledge of cognition and regulation of cognition (as cited Tüzün& Topcu, 2010). As knowledge of cognition refers to what individuals know about their own cognition, regulation of cognition refers to metacognitive activities that help regulate and control one's thinking and learning (Schraw andMoshman 1995, as cited Tüzün&Topcu, 2010). So, we can say that metacognition is a selfregulatory skill in which individual monitors his learning process. If we look at from Vygotksy's perspective, his theory is put under the social constructivism, his sociocultural theory's aim to provide self-regulated learners. Self regulation also requires metacognitive mediators such as planning, monitoring and evaluating (Schunk, 2008). Metacognitive strategies for selecting and monitoring mental functions promote creative and critical thinking. And for instruction, promoting thinking skills is important because it encourages individual's construction of knowledge, promotes their curiosity, and helps to build upon their interests and prior experiences (Salmon, 2008). So, from a constructivist perspective, self- regulation and metacognition cannot be separated because metacognition cover self regulation. Although Vygotksy did not use of particular term of metacognition, he asserted that "consciousness and deliberate control are the principal contributions of the school years".
Constructivist theories claims that, learners have active role in their construction of undertsandings and knowledge. This process requires self-organization ofexperience, and requires that students regulate their own cognitive structures, interact new meanings from existing knowledge, and an awareness of current knowledge structures. Therefore, I think, constructivism not only emphasize the constructive process, but also emphasize to be aware and control the construction process. So, from a cognitive constructive perspective, self-regulation, and self-awareness can take into account under the contruct of metacognition. And, it is clear that metacognition and critical thinking are rooted in the constructivist theory (Tsai, 2001).
For contructivist theories, contructing knowledge individualy with the interaction in the environmet also includes engaging in higher-level thinking and problem solving (Driver, Asoko, Leach, Mortimer, & Scott, 1994; as cited Duffy& Jonassen, 1992). In my opinion higher level thinking skills also refers metacognitive skills such as selecting appropriate strategies to achieve desired product, monitoring and evaluating efficiency of one's learning.
According to Tüzün and Topcu (2010), many researches indicates that metacognitively aware students are more strategic and perform better in problem solving situations than unaware students. I think, metacognitively aware students can easily make planning, sequencing, monitoring, and reflecting and it improves their performance. While learners are constructing their own understandings of the world to be metacognitively active can lead improve their performance and make learning better and faster (Moore, 2004).
So, to sum up metacognition is an aspect of constructivist view because it lead monitoring and regulating learning process when individuals construct knowledge by internalizing it from within, in interaction with the environment (Tsai, 2001).
Criticism of Constructivism
Constructivist theory emphasizes that individuals construct their own understandings or knowledge when they attempt to make sense of their experiences through the interaction of existing understandings and immediate learning environment (Cannella & Reiff, 1994; Richardson, 1997; as cited Liu&Matthews, 2005). With the emergence of constructivist view in 1970's also many criticism has emerged. In this paper I am going to discuss criticism of constructivism.
The first main criticism of constructivism is that there is no absolute only one truth, individual construct his truth in his mind. According to constructivist view, all individuals cannot be expected to have given or uniform cognition (Liu&Matthews, 2005). It means that all knowledge is subjective. According to radical constructivism, the knowledge is not objective 'truth', internal knowledge cannot match the external reality; it is an individual interpretation of experience (von Glasersfeld, 1995, as cited Schunk, 2008)). Briefly, knowledge is constructed by the learner within the activity was experienced in the context. Also, social constructivist's claims that truth is not the objective reality or experiential reality, but rather socially constructed agreed upon truth. However, in learning environment it can lead misunderstandings and it contrast with epistemological relativism (Liu&Matthews, 2005). Constructivism also de-emphasizes the correct answer or single interpretations. It focuses on learning process not learning product. In our educational system to evaluate of process cannot be possible for crowded classes. If there is no absolute truth, we must accept learners' all constructions as a truth though it is not appropriate with the external reality. For example, from constructivist perspective if learner thoughts that earth's shape is linear through his old experiences, although it is not an external reality we should accept it as his own construct. At this point we have faced with other criticisms that low ability learners or novices have difficulties in constructivist environment. Sweller claims that novices do not understand the underlying mental models necessary for "learning by doing" (Sweller, 1988; as cited Liu& Matthews, 2005). And Mayer (2004), after reviewed the literature from today to before fifty years ago he found that there is no empirical data which support using the constructivism's pure discovery rather he suggests the use of guided discovery. According to Mayer (2004), critics claim that "learning by doing" is useful for more knowledgeable learners than less knowledgeable one. So, the constructivist teaching technique is not appropriate for novices. In my opinion, at early ages, constructivism is not an appropriate teaching strategy. Because, to construct external reality of real world, learners should have basic prior knowledge and required cognitive structures and experiences. Also some critics found constructivism is elitist. They see constructivism as a progressive educational strategy. So they believe that it better works children who have privileged backgrounds and creates inequality (Hirsch, 2005, as cited Liu& Matthews, 2005).
The other main criticism of constructivism is that while constructivist teaching approaches, including one-to one or small group classroom interaction, it cannot always guarantee teaching effectiveness. For example in China, traditional teaching approach in large classes of 50 to 70 students more effective than constructivist learning strategies. (Biggs, 1998; Jin and Cortazzi, 1998; as cited Liu& Matthews, 2005).
Lastly, as I mentioned above social constructivism leads group works. While in a cooperative group learners construct their shared understandings some learners can dominate the group's conclusions and the others are forced to accept someone else's truth.
Although there are some criticisms to constructivist theory, it is clear that the study of human development has benefited from this theory from 1970's to nowadays. So we cannot not ignore contributions of this theory its roots come from Piaget, Vygotsky, Bruner etc. for learning. It brings us new perspective for educational area.