"What happens to domain knowledge on its way into the school curriculum?" The article explores this question from a systems view of the knowledge transformation process. This process is not only bound to "contextual knowledge" about "social forces" but also to the school's own "educational knowledge" framework. Further, utilizing knowledge depends on images of "learning" and "learners" which have a powerful impact on the "enacted" school curriculum ("instructional knowledge"). The rationale "and" meaningfulness of a syllabus or a curriculum, of materials, media or textbooks also affect what is learned and taught ("curriculum knowledge"). In addition, our images of meaningful learning filter how domain knowledge is represented in the curriculum and put into practice. A conceptual framework is developed to understand the complexity of knowledge transformation with regard to learning purposes and recommendations for research. (Contains 2 figures, 1 table and 1 note.)