With multi-channel biochemical screening becoming more widely used, it is necessary that normal values be established that will pertain to the population being screened. Statistically, results derived from a sample can be applied only to the population from which the sample was drawn. Thus, normal values derived from the typical sample of "young American volunteers employed in the hospital and apparently healthy" cannot validly be applied to members of a hospital population. Logically, it would be more valid to examine the values of a large sample of patients and determine the normal values by use of statistical methods. Presented in this paper are sections of an extensive statistical study performed on a hospital population using the SMA-12/60. It is hoped that this study may serve as useful guidelines for those technologists who believe that normal values should be established for a given laboratory, method and population.