The authors identified factors affecting problem finding depending on degree of structure of problem situation--either ill or moderately structured. Fifth-grade students (N = 115) were randomly assigned to 2 groups: Group 1 (n = 60) accomplished the ill-structured task; Group 2 (n = 55) performed the moderately structured task. Results indicated that the degree of structure of problem situation influenced variables affecting problem finding. In the ill-structured problem situation, scientific knowledge and personality traits positively affected problem finding, and divergent thinking negatively affected problem finding. In the moderately structured problem situation, divergent thinking and intrinsic motivation positively affected problem finding. Findings suggest that considering the degree of structure of problem situation helps teachers compose instruction methods to enhance students' problem-finding performance. (Contains 6 tables.)