The current research investigates the efficacy of the case-based instructional method for teacher education when seductive details (i.e. interesting but extraneous details) are included or removed. Aspiring teachers (n = 108) learned about principles of writing effective feedback in a text-based lesson without a description of a classroom case (C control), with a classroom case that contained seductive details (SD group), or with a classroom case that did not contain seductive details (NSD group). All participants then took retention and transfer tests. Results indicated equivalent group performance on retention, but improved performance for the NSD group compared to the SD group on transfer (d = 0.64). Results encourage the use of cognitive design principles to support meaningful learning when using classroom cases in instruction. (Contains 2 tables.)