functioning has been identified this is the standard against which all other performance is measured. In general a single high score should not be relied upon, unless supported from other observations. In most cases the best performance estimate will be based on a cluster of highest scores and a single. For example, a doctor who performs in tests at an average level but who has displayed superior function in prior education and occupational performance is obviously underperforming upon potential in test and past education and occupation would represent the best estimate. The advantage of the best estimate method is that a broad range of abilities are taken into account and neuropsychologists are not bound to any single battery of tests. A review examined whether hold tests, best estimate or regression equation methods were most accurate in predicting overall IQ (full scale IQ) as determined by Wechsler Adult Intelligence Scale (WAIS-R) in a non-neurologically impaired population. It was found that different methods were more accurate depending on the IQ level of participants e.g. WRAT-3 (hold test) was most accurate for those of below average intelligence, NAART (hold test) was most accurate for those of average intelligence and the best estimate method was most accurate for above average intelligence. This provides support for the idea that no single method is superior in all cases and a combination of approaches is most appropriate in clinical practice. References Neuropsychological tests Cognitive tests