Hyperbolic Value Addition and General Models of Animal Choice

Three mathematical models of choice-the contextual-choice model ( R. Grace, 1994 ), delay-reduction theory ( N. Squires & E. Fantino, 1971 ), and a new model called the hyperbolic value-added model -were compared in their ability to predict the results from a wide variety of experiments with animal subjects. When supplied with 2 or 3 free parameters, all 3 models made fairly accurate predictions for a large set of experiments that used concurrent-chain procedures. One advantage of the hyperbolic value-added model is that it is derived from a simpler model that makes accurate predictions for many experiments using discrete-trial adjusting-delay procedures. Some results favor the hyperbolic value-added model and delay-reduction theory over the contextual-choice model, but more data are needed from choice situations for which the models make distinctly different predictions.