Model Specification in Stationary Random Fields

The problems of model specification in one‐ and two‐dimensional stationary random fields are considered, with particular reference to the class of spatial autoregressions. The role of the autocorrelation function is discussed and it is shown to have a valuable exploratory use, especially in identifying directional bias in random fields. It is recommended that this analysis be supplemented by a likelihood‐ratio test, which permits more precise tests of hypotheses about the form of the underlying model.