The goal of this article is (a) to review a series of measurement standards for group and individual-patient applications of cognitive tests for Alzheimer's disease (AD); and (b) to review the literature and to use specific data from the NORMACODEM (a project of standardization of cognitive and functional tools for AD) to evaluate the measurement standards of the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog). Seven measurement standards for group and individual patient use were evaluated: practicality, extent of measurement, depth of measurement, cross-sectional precision, longitudinal precision, validity, and standardization. The results indicated that ADAS-Cog meets practicality standards, that the scoring method is not difficult, but training is needed to administer the test. In comparison with other rating scales, the ADAS-Cog is regarded as more comprehensive, although it is not a substitute for an extensive neuropsychological test. The ADAS-Cog is not a tool that is suitable for primary care physicians, although it is a valuable screening test that has utility in both early detection (diagnosis) and staging of AD, and is useful in the severity range of Global Dementia stages 1 to 6. Interrater reliability coefficients for the ADAS-Cog satisfy recommended standards, and the test shows good internal consistency and reproducibility. Age and education are associated with the ADAS-Cog score. There is, however, a lack of standardization, which restricts the comparability of study results, and test materials remain unpublished.