Abstract. Teaching and learning chemistry in a context based curriculum requires the process of decontextualization to make chemistry concepts transferable to other contexts. The method of progressive concept mapping is promising to support this process. Research results report difficulties in teaching chemical concepts like the solution concept because students often have resistant alternative conceptions of the processes, formed in everyday life experiences. It is assumed that the process of externalizing concept with the method of concept mapping and also communicating the maps in a group can support the awareness of misconceptions and also to overcome them. In a study 13 to 15 year old students learning chemistry through the German curriculum Chemistry in Context (ChiK) use the computer based concept mapping program CmapTools as a progressive reflecting tool. The experimental design compared this method to the conventional ChiK portfolio method “Lernbegleitbogen” (LBB). Additional the condition reflecting in pairs or alone is altered. The presentation will report theory, design and instruments of the study as well as the results of the pre-study in two classes with 60 students.