Tasks can range in difficulty along one continuum from cognitively undemanding to cognitively demanding; and along another continuum from context-embedded to context-reduced. A context-embedded task is one in which the student has access to a range of additional visual and oral cues; for example a one with illustrations of what is being talked about. A context-reduced task is one such as listening to a lecture or reading dense text, where there are no other sources of help than the language itself. A task which is both cognitively demanding and context- reduced, is likely to be the most difficult for students.