Analysis of dose-effect relations

The conventional models for interpretation of dose-effect relations have, at best, heuristic values but are often rather misleading. In spite of this, dose-effect curves are still characterised and classified according to these models. The so called 'hit-number' though widely used ia always accompanied by the statement that it is, in fact, not a hit-number. This paper discusses the continued use of traditional notions, emphasising the difficulties involved in the traditional concepts. Other topics dealt with are: the number of interacting absorption events; diameter of the sensitive site; Rossi's concept of local energy density. A numerical example for determination of mean inactivation dose and is included in the appendix