When entering the classroom, adolescents already hold various conceptions on science topics. Concept maps may function as useful tools to reveal such conceptions although labor-intensive analysis often prevents application in typical classroom situations. The authors aimed to provide teachers with an appropriate approach to analyze students' concept maps within daily school routine. They intended to conclude qualitative changes from analyzing quantitative parameters. To test the approach, high school students were asked to map their conceptions before and after attending an educational program on climate change. For the analyses, quantitative as well as qualitative methods were applied. A comparison of pre- and postmaps pointed to a conceptual change. From strong correlations between qualitative and quantitative parameters we assumed our approach to be applicable. Due to its simple and barely time-consuming handling, the authors' approach is suitable for application in conventional classroom situations and may contribute to inform teachers about students' conceptions.