The aim of the article is to show how substantial qualitative material consisting of graphic cognitive maps can be analysed by using digital CmapTools, Excel and SPSS. Evidence is provided of how qualitative and quantitative methods can be combined in educational research by transforming qualitative data into quantitative data to facilitate discoveries of patterns in the data. Examples are drawn from research on conceptions of both different teaching methods and on school leadership related to school development. The rationale for using cognitive map interviews as a method for data collection is presented. Cognitive, theoretical and methodological issues are discussed. Tools that might be used to facilitate detection of patterns in a substantial number of maps are reviewed. It is demonstrated how unique expressions on individual cognitive maps visualizing different understandings can be transformed into a common system of concepts which make it possible to use quantitative methods to find patterns in comprehensive qualitative data. (Contains 3 tables and 1 figure.)