A direct deduction of the constant process used in the method of right and wrong cases.

Abstract

The object of this article is to show how the Constant or Fechner-Miiller-Urban Process of calculating thresholds can be directly deduced from first principles.The historical development of the process is first traced, and then contrasted with the direct deduction.The latter throws into clearer relief the nature of the assumptions and approximations made, and justifies Urban's, as against Miiller's, Table of Weights.