A simple statistic to test generalized palindromic symmetry model in a 4 x 4 contingency table

Abstract

For a 4x4 contingency table, this note gives a simple statistic to test the goodness-of-fit of the generalized palindromic symmetry (GPS) model considered by McCullagh (1978). Also an asymptotic confidence interval for a parameter of interest in the GPS model is given. Two sets of unaided vision data are used as example.