Constructivism is a learning theory where students construct their own knowledge and meaning through experiences. Key founders include Piaget who observed how children learn, and Montessori. In a constructivist classroom, the teacher does not follow a set curriculum but tailors lessons to students' responses. Students rely on questions and dialogue rather than memorization, and apply prior knowledge to draw their own conclusions through exploration and research aided by technology. While encouraging creativity, the theory may not be practical for today's classrooms which often lack sufficient tools and have large class sizes.