In this article the authors describe how they engaged pre-service teachers (PSTs) in a comparison activity of two Standards-based lessons. The article presents PSTs' perceptions of the affordances and constraints within each lesson, interpret these results and present implications for further research. Because "Standards"-based curriculum materials are becoming ubiquitous in schools (Archer, 2005; Remillard, 2005), there is a need for teacher education programs to prepare PSTs to be able to perceive the intended meaning of, mobilize the potential of, and continually develop their pedagogy through curricular resources. The authors' overarching research concerns the design of research-based activities for the elementary mathematics methods course that will allow preservice teachers (PSTs) to learn about- and from- "Standards"-based curricular materials. They posit these types of activities can enable PSTs to move along a trajectory towards expert curriculum use. [For the complete proceedings, see ED585874.]