Those who believe that students learn best when they are supported in constructing knowledge through guided interaction with ideas, resources, tools, and other learners generally follow a constructivist philosophy. We can only know the world through our mental framework which transforms, organizes, and interprets our perceptions. This mental framework is constructed and evolves through development as we interact with our environment and try to make sense of our experiences. It is the teacher's role to assist students in making sense of the input in the classroom. The teacher must structure the environment and the learner must structure their own understanding of it.
Constructions come about through assimilation and accommodation.
This is based on Piaget's theory that we assimilate information based on our existing mental framework. Learning is an organic process of invention, rather than a mechanical process of accumulating facts. The learner must be provided with experiences of hypothesizing and predicting, manipulating objects and data, researching answers, imagining, investigating, and inventing in order to construct knowledge. Meaningful learning occurs through reflection and resolution of cognitive conflict which negates earlier, incomplete levels of understanding. The teacher can only mediate in this process.