A new methodology is introduced for spatial sampling design when the variab
le of interest cannot be directly observed, but information on it can be ob
tained by sampling a related variable, and estimation of the underlying mod
el is required. An approach based on entropy has been proposed by Bueso. An
gulo, and Alonso (1198, Environ. Ecol. Statist. 5. No. 1, 29-44) in the cas
e where a model for the involved variables is given. However. in some cases
a predetermined structure modelling the behaviour of the variables cannot
be assumed. In this context, we derive criteria ibr solving the design prob
lem based on the stochastic complexity theory and on the philosophy of the
EM algorithm. For applying the proposed criteria a computational procedure
is developed based on the supplemented EM algorithms. The methodology is il
lustrated with a numerical example. (C) 1999 Academic Press.