In applications of the Hillmer-Tiao model-based signal extraction approach to seasonal adjustment (see Hillmer, Bell and Tiao (1983) or Burma; (1980)), there usually is a white noise component which must be divided among the seasonal and nonseasonal components, or assigned wholly to one of them (see the example in section 4). This assignment determines the covariance structure which must be specified before the optimal estimates, or, essentially equivalently, the filters used to obtain them, can be determined. Recently, Watson (1984) proposed the use of a minimax criterion related to mean square component estimation-error for making this assignment. His approach is quite attractive, due in part to additional appealing properties he demonstrates for some of the solutions to his minimax problem.