An effective strategy for improving problem-solving ability is fostering students' questionposing capabilities through the use of real-world problems. This article describes research on scientific question-posing capabilities among 10th-grade students who were studying air quality in a cooperative way, using the jigsaw method. Case studies and analyses of daily problems and dilemmas were integrated within the module the Quality of Air around Us, which was designed and developed specially for this research. The students were required to pose questions and cope with real-life problems while practicing a variety of learning activities, such as reading press or scientific articles, analyzing tables and graphs, and creating posters and advertisements that related to the problem. The students' question-posing skills were evaluated by using pre-and postcase study questionnaires. We found the number, orientation, and complexity of questions students posed to be three indices of question-posing capability. Following study of the Quality of Air around Us module, a significant increase was observed in the factors of number and complexity of questions students posed. The difference between students at high and low academic levels in the extent of increase in both number and complexity of posed questions was significant. As for orientation, the percentage of solution-and opinion-oriented questions increased in the posttest, and fewer questions dealt with the problem and related hazards. This indicates an increase in students' awareness of the need for and feasibility of seeking practical solutions to a given problem, as well as considerable improvement of their ability to analyze a related case study. On the basis of these findings, we recommend incorporating analysis of question-posing capability as an alternative evaluation method. To this end, fostering of question posing into the case study-based teaching/learning approach is the preferred strategy, in particular when environmental aspects are involved.