Teacher educators drive preservice teachers' learning about teaching particularly through feedback. The learning materials produced by preservice teachers also play a crucial role in English language teacher training but may not be receiving the necessary attention in teacher education programs. Preservice teachers lack formal teaching experiences, which may result in their overemphasizing material delivery while underemphasizing material suitability. Providing teacher educators with criteria for evaluating learning materials developed by preservice teachers could aid in their providing quality formative feedback. Therefore, this study was designed to construct a research-based contextualized evaluation checklist for learning materials. Adopting a systematic yet flexible design-based method allowed for the integration of design and intervention to develop a solution for this targeted educational problem. The researchers adopted a three-phase process for this study: analysis and exploration of a teacher educator's needs and extant literature on learning materials; design and construction; and evaluation and reflection. Learning materials designed by a preservice teacher were used to pilot the checklist. The results showed a need for refinement to form the final evaluation checklist. The checklist can be used by teacher educators for preservice teacher evaluation purposes or by preservice teachers as a quality check.