As teacher education shifts to focus on teaching beginners to do the work of teaching, assessments need to shift to focus on assessing practice. We focus on one teaching practice, eliciting student thinking, in the context of elementary mathematics. We describe assessments in two contexts (field and simulation). For each assessment, we describe the eliciting of three prospective teachers what could be seen about the skills of group of prospective teachers (N = 44). We report on how three prospective teachers had differing opportunities to demonstrate their skills in the context of the field assessment, but similar opportunities in the context of the simulation assessment. Although both contexts make important contributions, in each case, contributions are counterbalanced are by significant challenges. Although the authors do not argue for one assessment context over the other, they offer insights into the affordances and challenges of each so that teacher educators can make responsible decisions.