Objective: For individuals with neurologic disorders, self-awareness of cognitive impairment is associated with improved treatment course and clinical outcome. However, methods for assessment of levels of self-awareness are limited, and most require collateral information, which may not be readily available. Although distortions in self-awareness are most often associated with low cognitive ability, the frequently mixed pattern of cognitive strengths and deficits in individuals with neurologic disorders complicates assessment. The present study explores relationships between actual test performance and self-ratings, utilizing a brief probe administered during testing. The "common-metric" approach solicits self-appraisal ratings in percentile equivalents and capitalizes on available normative data for specific standardized neuropsychological tests to allow direct comparisons. Method: A convenience sample of 199 adults recruited from community sources participated in this study, including healthy adults and neuropsychologically "at-risk" volunteers who were HIV positive and/or endorsing heavy current alcohol consumption. Immediately following completion of standardized neuropsychological tests, participants estimated their own percentile ranking. Results: Across study groups, participant's estimates of their own percentile rank were modestly correlated with actual performance ranking. Highest correlations were obtained for tests of learning, memory and conceptual reasoning, and executive function, with smaller correlations for simple tests of motor and psychomotor speed. Conclusions: The study reveals normal biases affecting the self-appraisal during standardized testing, and suggests that a common-metric approach for assessing self-appraisal may play a role in establishing clinical thresholds and identifying and quantifying reductions in insight in persons with neuropsychological deficits