We all work in less than ideal circumstances for one reason or another, and it is not always possible to have what we would consider optimum conditions for assessment. In other words, we operate within certain practical constraints. One of the most common of these is time restriction: ideally we might like to trial our tests and exams before letting students loose on them, and we might then like to remove less reliable items from the test and adjust our mark schemes to make them tighter. If you are teaching several different modules, however, each with just 15 or 20 students on it, you are simply not going to have time to do this. Such approaches are only feasible and cost-effective in mass assessment programmes, such as those run by the national awarding bodies for GCSE, 'AS' or 'A2' levels, or by The Open University. Similarly, timetable and resource constraints may well mean it is not possible for all students on a module to be assessed via individual oral presentations twice a year, and group assessments may have to be used instead. In other words, whatever assessment instrument we use also has to be practical.