So far, only weak utility functions have been used to represent strict part
ial orders, but such a representation is not completely satisfactory, since
we can not reconstruct the preference relation by simply knowing the weak
utility function. The purpose of this paper is to present a type of numeric
al representation for strict partial orders, in such a way that recovering
the preference relation is possible. Taking into account that (2(R), supers
et of) is a strict partial order, we consider set-valued utilities, namely,
set-valued mappings, such that they admit a selection which is a weak util
ity function. (C) 1999 Academic Press.