Response Surface Methodology for Dose-Response Research

Due to the difficulties encountered in dose-response research, many studies determine whether a dose-response relationship exists, but do not establish the dosage for the optimal outcome. Response surface methodology (RSM), introduced by Box and Wilson in 1951, is an experimental design method that aims to find the conditions that lead to the optimal response, using the least number of observations and trials. RSM is an iterative approach that takes the guesswork out of experimentation by allowing the researcher to learn about the amount of replication needed, the location of the experimental region of interest, the appropriate transformation and scaling of the variables and the degree of complexity of the model at different stages of experimentation. Furthermore, the method clearly suggests to the researcher how the dosage of the inputs should be varied in future experimental runs in order to attain the optimal outcome. This reduces the cost of experimentation while finding the optimum as quickly as possible. This tutorial focuses on the key steps of the RSM that include determining factor levels, choosing an appropriate model and analyzing the results by studying the response surface and applying optimization techniques that would lead to the optimal conditions. Using examples and data from the field, this tutorial introduces RSM as an efficient method for determining optimal dosage in physical education, exercise science and health related research.