Recent interest in the empirical exploration of patients' awareness in relation to their clinical states has resulted in a range of approaches taken to evaluate such awareness. These approaches vary in terms of the bases on which awareness is determined and rated, the contents of the measures used, the level of detail and complexity of judgements required, etc. The approaches use different definitions and objects of awareness and hence give rise to different (and on occasions divergent) awareness phenomena. Such differences help to explain both the contradictory nature of published results and the difficulties involved in generalising from them. In practical terms, these differences should encourage the development of management and rehabilitation strategies that are individual to specific phenomena of awareness.