In the new learning approach assessment is integrated in learning and instruction and addresses complex traits (the abilities, the characteristics in a specific domain) of students. To match this new approach, new types of assessment are developed, like peer assessment or competence assessment. The development of these new assessments is an expensive and intensive activity. Exchange initiatives promise to reduce those efforts by the re-use of materials. But they also raise questions: is it a complete assessment or are there specific parts of an assessment that can be re-used? And is re-use limited to particular item formats? In order to support the re-use of both new and traditional assessment types an educational model for assessment is developed. In this article we present this model. The model is validated against [Stiggins, R. J. (1992). Het ontwerpen en ontwikkelen van performance-assessment toetsen [Design and development of performance assessments]. In J. W. M. Kessels, & C. A. Smit (Eds.). Opleiders in organisaties/Capita Selecta (pp. 75-91). Deventer: Kluwer (afl. 10)] guidelines for the development of performance assessments, the four-process framework of [Almond, R. G., Steinberg, L., & Mislevy, R. J. (2001). A sample assessment using the four-process framework. CSE Report 543. Center for study of evaluation, University of California, Los Angeles. Retrieved November 15, 2005 from http://www.cse.ucla.edu/cresst/reports/tech543.pdf; Almond, R. G., Steinberg, L., & Mislevy, R. J. (2003). A four-process architecture for assessment delivery, with connections to assessment design. CSE Report 616. Center for study of evaluation. University of California, Los Angeles], a specification for the exchange and interoperability of assessments and performance assessment as a new type of assessment. The educational model for assessment gives new input to the alignment of the teaching, learning and assessment.