This paper argues that the vertical spread of computer-assisted language learning (CALL), i.e., a spread throughout language materials and curricula, makes it difficult to draw a clear distinction between CALL and other language materials. In view of the emphasis that teachers, researchers, and administrators have placed on evaluating CALL, I argue that some valuable lessons about materials evaluation can be drawn from reflection on issues in CALL evaluation. In particular, I discuss the opportunities for professionals to reconsider assumptions held about comparative research, draw upon research perspectives and methods from applied linguistics in materials evaluation, and include critical perspectives which examine the opportunities that materials offer language learners to engage in language and culture learning.