ABSTRACT
Commercially published, traditional textbooks predominate mathematics curriculum materials in U.S. classrooms and to a great extent determine teaching practices (Goodlad, 1984), even in the context of reform efforts (Grant, Peterson, & Shojgreen-Downer, 1996). Various standards (National Council of Teachers of Mathematics [NCTM], 1989) and state and local curriculum frameworks are designed to govern or at least guide these materials. However, publishers attempt to meet the criteria, including scope and sequence requirements, of all such frameworks, and thus the educational vision of any one is, at best, diluted. Moreover, teachers’ reliance on textbooks minimizes any effect of such visions. Thus, a primary cause of the poor performance of U.S. students in mathematics (Kouba et al., 1988; McKnight, Travers, Crosswhite, & Swafford, 1985; Mullis et al., 1997) is the curriculum, both in what topics are treated and how they are treated (Clements & Battista, 1992; Porter, 1989). In one main focus of study, geometry, for example, textbooks are not only ineffective in promoting higher levels of geometric thinking (Fuys, Geddes, & Tischler, 1988), they often hinder this development (Jaime, Chapa, & Gutiérrez, 1992; Mansfield & Happs, 1992).
