While the planning of assessments is traditionally considered to be an important part of instructional design (e.g., Dick et al., 2011), seeing assessment planning as a design task and process is somewhat unusual. 1 We argue that it should be seen as a design challenge, in particular when the competences to be assessed are complex, when the objective is for the assessment to be authentic, and when the assessment is supposed to be integrated into information technology-rich environments. Distinguishing the output of the assessment design process—the design product—from the actual assessment (a computer-based problem solving ‘item’, for instance) has two important advantages. First, keeping the design separate from its realisation (implementation) makes it easier to implement the design in different formats: for instance, in a paper-based format and delivered in digital format, or across different learning management systems (see, for example the work on question and test interoperability done by IMS 2 ). Second, to the extent that the language used for representing the design is closer to the pedagogical than the technical level, the rationale for and logic of the assessment is expressed in a form that can be understood by teachers, students, and other stakeholders, such as parents. Thinking about and communicating the rationale of an assessment is more important the more the assessment becomes a resource for learning. We mean this not only in the sense that assessment ‘drives’ teaching and learning (Firestone et al., 2004), but also in the sense that learners interpret assessment tasks in terms of epistemic implications: What does the assessment task say about what is important to know, and about the nature of knowledge/knowing (Chinn et al., 2011)? And when the learning addresses professional competences, in addition to skills and knowledge, the assessment tasks will also send signals to the learners regarding professional identity: What is it that makes for being a competent practitioner, a teacher or nurse, for instance?