Similarly according to Moloi et al. (as cited in Mtika & Gates, 2010), group work is one of the strategies that can be useful in student-centered approaches. It does not only help students to discuss and share ideas with each other, but it also helps to improve students' understanding of some concepts and develop their communication skills. In the student-centered classroom, the teacher has to think of students' needs and the classroom is considered as a place where students work together, in groups and as individuals by encouraging them to take part in the learning process all the time (Jones, 2007). In the student-centered classroom, the teacher should know about their students' background. Teachers should consider what they may know or do not know about their students because it helps to create the classroom conditions that are responsive to the learning needs of the students (Hodson, 2002). Furthermore, in social constructivist classrooms the relationship between teacher and students are much more dynamically involved, so that the teacher's role is much more demanding to allow and actively promote recognition, evaluation, and reconstruction (Gunstone and Northfield as cited in Hand et al., 1997).