An analytical investigation is described which relates errors in spatial registration of multispectral and multitemporal data sets to error in classification. Of particular interest is the classification of large areas of crops. Misregis-tration effects on the statistics of field-center and boundary pixels are studied. The possible results when more than two classes are involved is also considered. An analytical model allowing numerical calculation of the probability of error in a number of specific cases is developed and requirements for a general model is discussed.