WHY USE PERFORMANCE-BASED MEASURES?
The primary reason for using objective performance-based measures, as opposed to other measurement strategies such as self-report or informant-report, is that they afford a less biased assessment of performance. In addition, they can be adapted to the unique needs of a population and task/behavior in question. For example, the difficulty level of the tasks, or the language, or contextual cues can be adjusted. The skills required for different aspects of everyday functioning (e.g., work, school, everyday activities of living, social activities) generally differ depending on the functional domain assessed (e.g., social vs. employment).
The types of performance-based assessments that are available vary considerably, and include standardized tests of cognitive abilities (that are related to but do not directly assess functional skills), paper-and-pencil simulations of everyday tasks, and realistic, virtual-reality performance scenarios that directly model real-world functional activities. They also include observational strategies and physiological indices. Obviously, these types of measures vary considerably in terms of issues such as administration requirements, scoring algorithms, the nature of the data collected, and the type of data required for validation. With respect to the latter, novel realistic computer-based simulations have the least demands for assessment of convergent validity, and performance-based neuropsychological tests have the best data in terms of psychometric properties and alternate forms.