Critiquing and adapting curriculum materials are essential teaching practices but challenging for many preservice teachers. This study explores the use of educative curriculum materials--materials intended to support both teacher and student learning--to help preservice elementary teachers develop their pedagogical design capacity for critiquing and adapting lessons. Preservice teachers received educative supports highlighting pedagogical principles and rationales for those principles. When provided with educative supports, most individuals attended to the principles targeted in the supports, engaged in an in-depth analysis with regard to the principles, and used the rationales from the supports to justify their analyses. However, few continued to do so in subsequent analyses when they no longer received support. Implications for science teacher education and curriculum design are discussed.