The document outlines the cognitive development theories of Jean Piaget, Lev Vygotsky, and Jerome Bruner, highlighting key features of each theorist's approach. Piaget's theory describes stages of cognitive development characterized by children's active construction of knowledge and the importance of schemas, while Vygotsky emphasizes sociocultural interactions and tools in learning, introducing concepts like the zone of proximal development. Bruner's theory focuses on discovery learning and problem-solving through stages of representation, advocating for a curriculum that supports active engagement and collaboration in educational settings.