The idea is that ideas develop over time and that a student's level of understanding can be influenced by many factors (Lesh and Lehrer, 2003). The challenge is to provide students with the opportunity to "extend, revise, reorganize, refine, modify, or adapt the constructs (or conceptual systems) they possess" rather than defining or creating new ones. new ideas (Lesh and Lehrer, 2003). Vygotsky (1978) mentions that language has an influence on a student's thinking, but that models and modeling perspectives extend beyond just language to the extent that there are other influences of the a student's culture beyond language that have an influence on his or her thinking (Cobb and McClain, 2001). How models and modeling perspectives develop conceptual tools varies along various dimensions, while Vygotsky focuses on the internalization of experience (Lesh, 2002). Thus, Lesh extends Vygotsky's zone of proximal development to a multidimensional region in which there are various ways to develop understanding of a concept as well as different paths to take while exploring the different regions (Lesh & Lehrer,