In an effort to better prepare science teachers to engage in high-leverage practices, this study investigates the choices and rationales of preservice science teachers in planning elicitation strategies and describes how their understandings about the elicitation of students’ ideas changed over time. Four cohorts of preservice science teachers engaged in a cycle of modified lesson study focused on the elicitation of student ideas. Findings suggest that the participants focused on revising the elicitation task to achieve greater task clarity and student participation and to provide more opportunities for individual thinking. One notable outcome of the study is the need for a greater conceptual distinction in science teacher education between elicitation practices in which resources for student thinking are identified, and assessment practices that seek students’ progress toward learning goals.