Standards of assessment of treatment effect in Alzheimer''s disease have been wanting. We report here a comparison of seven methods of assessment of the severity of Alzheimer''s disease used in demented subjects (n = 18) and in nondemented controls (n = 18). The instruments tested were the Names Learning test, the Orientation test, the Mini-Mental State Examination, the Alzheimer''s Staging Scale (the AZSS), the Global Deterioration Scale, the Clinical Dementia Rating Scale, and the Alzheimer''s Deficit Scale (ADS). Two examiners did the testing per telephone methodology, and test/retest design. Results showed all tests to be reliable. A ceiling and/or basement effect was noted in all but the AZSS and the ADS.