The teacher’s belief system is paramount.
A teacher who believes that social constructivism (Vygotsky, 1978) or situated learning is useless, will find the work and effort for accomplishing PBL to outweigh its benefits.
The tenets of constructivism, in its many versions, underlie PBL
designs (Grant, 2002). In PBL, the teachers’ role necessitates that they allow all students to engage in developing personally and collaboratively negotiated meanings from the learning event