Research conducted after the publication of the original Dementia Rating Scale (DRS) showed that both age and education contribute significantly to DRS subscale and Total Scores. This finding, along with several other factors, provided the impetus for the development of the DRS-2. The DRS-2 measures cognitive function at lower ability levels whereas some other evaluation instruments are limited by floor effects. The DRS-2 also can be used to track changes in cognitive status over time. By design, the DRS-2 measures deficits in a large range of higher cortical functions and differentiate deficits of varying severity levels.