ABSTRACT
Useful assessment systems balance the qualities of practicality, reliability, validity and beneficial impact. The most practical assessment systems cost little and are easy to administer, but they are unlikely to give useful results. Investment in improving reliability, validity and beneficial consequences will make results more useful, but inevitably increase the costs of the assessment system. Assessment developers need to persuade other stakeholders that it is worth investing in tools that give consistent results, have a sound basis in theory and encourage good learning practices. Suggestions are provided on how to collect evidence for each of the four qualities in an assessment system and on how to use the evidence to improve a system over time.
