Most exceptionally able children spend far too much time practising skills already mastered and repeating tasks or doing assignments which they have already covered. Joseph Renzulli proposes that, to avoid this reputation, teachers should initially ascertain, by pre-testing, what skills exceptional children already have and in what curriculum areas they are already knowledgeable and experienced. This means that teachers have to know what their aims and objectives are in, for example, mathematics, reading, science, etc. Then a pupil's learning programme can be developed from his/her level of competence and knowledge. He calls this process of assessment prior to planning ‘Compacting’. The time thus ‘saved’ by omitting unnecessary practice or repetition can then be spent on extension activities.