[On the strategy of measuring in gerontology (author's transl)]

By the point counting method and empirical regression we investigated the aging changes in volume densities of histological structures in 43 human thyroid glands and in 42 human submandibular glands. Especially we wanted to show, how the change of the most important errors influences the shape of our aging curves. We had to take into consideration the statistical error, the error caused by the structural heterogenity, and the error caused by the interindividual variability. It was shown, that an increase of the exactness of measuring as well as a consideration of the structural heterogenity in the organs do not change the course of aging curves and 42 or 43 cases were sufficient for our investigations.