At what age and under what conditions do children systematically use probabilistic information in decision-making? How do they use it - as criteria for orienting selective information searches and/or as weights of values in the integration of information? With regard to these questions, the empirical research findings are poor and inconsistent. Against the background of two model classes of decision making (multiple strategy approach vs. connectionist approach) competing assumptions about decision making processes are derived. These assumptions are systematically investigated in a series of laboratory experiments on kindergarten children and school children in comparison to adults. The child-oriented decision environment developed for this purpose uses an information board and allows, in addition to the variation of task characteristics, the behavior-based measurement of the use of probabilities in information search and information integration. The results should not only help to clarify the above questions, but also to critically examine the basic assumptions of competing model classes of decision making.