[The role of the biometrician in dosage finding]

Biometrics is the science of mathematical models for biological processes and of methods for the design and analysis of biological experiments. By these tasks the role of the biometrician in the problem of dose-scheduling is determined. He has to develope mathematical models for the dose-response relationship and methods for the design and analysis of pharmacological and clinical experiments. In the paper the probit and logit model are discussed as examples of the mathematical approach to dose-response relationship. The problems of planning and analyzing bioassays are demonstrated. The pharmacological results can be applied to clinical investigations if they are related to standard drugs. The safety or risk of a drug can be measured by the therapeutic index, which is most important for the connection between pharmacological and clinical results. Finally the problem of repeated doses and accumulation is dealt with.