Constructivism in education has roots in epistemology, which - in philosophy - is a theory of knowledge, which is concerned with the logical categories of knowledge and its justificational basis. Epistemology also focuses on both the warranting of the subjective knowledge of a single knower and conventional knowledge. In constructivism, hence, it is recognized that the learner has prior knowledge and experiences, which are often determined by their social and cultural environment. Learning is therefore done by students' “constructing” knowledge out of their experiences. While the Behaviorist school of learning may help understand what students are doing, educators also need to know what students are thinking, and how to enrich what students are thinking. There are scholars who state that the constructivist view emerged as a reaction to the so-called "transmission model of education", including the realist philosophy that it is based on.