  Two-stage superposition choice procedures, which sequentially apply two
choice procedures so that the result of the first choice procedure is the input
for the second choice procedure, are studied. We define which of them satisfy
given normative conditions, showing how a final choice is changed due to the
changes of preferences or a set of feasible alternatives. A theorem is proved
showing which normative conditions are satisfied for two-stage choice
procedures based on different scoring rules, rules, using majority relation,
value function and tournament matrix. A complexity of two-stage choice
procedures as well as its runtime on real data are evaluated.
