ADDITIONAL RULES FOR THE TRANSFORMED UP-DOWN METHOD IN PSYCHOPHYSICS

In a classic paper, Levitt (1971) described an adaptive procedure for estimating points on the psychometric function known as the transforme d up-down method. Levitt discussed the assumptions of the method and p resented a brief table with simple rules that converge to a few differ ent points on the psychometric function. Levitt's original table conta ins only the simplest rules, and sparsely covers the range of the psyc hometric function. This paper provides a table with previously unpubli shed rules which cover the range of the psychometric function at 5% in tervals. There is a brief review of the major issues in adaptive testi ng. Technical issues such as the mean length and logical construction of the new rules are discussed.