Cognitive interviews were employed to systematically examine the cognitive validity of self-report survey items extensively used to assess classroom mastery goal structure. In a sample of elementary and middle school students, items were identified that functioned according to their intended meaning and those eliciting less accurate interpretations as conceptually defined by mastery goal structure cognitive validity criteria. Evidence suggested that items framed to focus on students' teachers (i.e., teacher goals) were more cognitively valid than were items that focused students on their classroom context. Items with abstract terms yielded less accurate interpretations. We discuss implications of determining the cognitive validity of scales used to assess achievement goal structure and related self-report instruments. (Contains 4 tables.)