New book chapter “Methods in Psychophysics” accepted for publication
in the forthcoming 4th edition of the “Stevens’ Handbook of Experimental Psychology” by Felix Wichmann and Frank Jäckel.
Typically researchers in psychology are interested in substantive issues about the mind---how we see, hear, categorize or reason about the world. To answer the multitude of yet unanswered substantive questions, one typically conducts experiments to collect data, analyses the data obtained, and then interprets them in the context of current theories and models. Here we look at some of the aspects of the first two steps, the collection and analysis of behavioral data from psychophysical experiments. We will concentrate on the various experimental designs for experiments of the threshold or just-noticeable difference (JND) type. Subsequent to data acquistion, we suggest to use Bayesian inference to estimate the psychometric function of a beta- binomial model as the default data analysis if there is a single independent variable. For multidimensional data and exploratory data analyses we briefly introduce multidimensional psychometric function estimation techniques making use of regularisation techniques from machine learning. We conclude our chapter with a discussion of the timeliness of the two commandments of psychophysics: “Know thy stimulus” by Wilson Geisler and “Thou shalt not be lazy (when gathering data)” we attribute to Karl Dallenbach.