Informativeness of functionals

We introduce the concept of informativeness of a continuous functional on a metric spaceX with respect to a setMX and a metric x. We pose the problem of finding the most informative functional. For some sets of continuous functions, this problem is solved by reduction to a subset of functionals given by the value of a function at a certain point.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 46, No. 9, pp. 1156–1163, September, 1994.