title: A likelihood ratio test for mixture effects.
abstract: Under certain circumstances, it is theoretically important to decide whether a difference between two conditions in mean reaction time (RT) results from a relatively uniform slowing of all the responses in the slower condition or from a mixture of some slowed trials with some unslowed ones. This article describes a likelihood ratio test that can be used to differentiate between these two possibilities and reports computer simulations examining the power and Type I error rate of the test under conditions similar to those encountered in RT research. A freely available computer program, called MIXTEST, can be used both to carry out the likelihood ratio test and to conduct simulations evaluating the performance of the test within various settings.
authors.affiliation: Department of Psychology, University of Otago, Dunedin, New Zealand. miller@psy.otago.ac.nz
authors.forename: Jeff
authors.initials: J
authors.lastname: Miller
mesh_terms: D035841:Behavioral Research / Q000706:statistics & numerical data*; D003198:Computer Simulation; D006801:Humans; D016013:Likelihood Functions; D011930:Reaction Time; D012984:Software; D016008:Statistical Distributions