This document outlines several key theorists in constructivism including Lev Vygotsky, Jerome Bruner, Jean Piaget, and John Dewey. Vygotsky believed that social interactions are important for cognitive development. Bruner thought learning occurs through doing activities. Piaget proposed children learn in stages through experiences. Dewey felt learning should relate to students' lives. Constructivism posits that learning is active and students build new ideas from past knowledge.