Concept maps (cmaps) are graphical tools that illustrate complex networks of interconnections between concepts. These can be used to illustrate the concept connections implicit in teaching syllabus content thus facilitating sense-making and meaningful learning. This paper sheds some light upon pre-service teachers’ understanding of the interconnectedness of basic concepts for the topic of “Data” as evidenced in their construction of comprehensive cmaps. The illustrative networks designed by pre-service teachers were analyzed in relation to what connections were made and the quality of statements between connecting links/nodes. The results showed the variety and complexity of the interconnectedness of pre-service teachers’ understanding of the concepts. Implications for both teaching and research are provided.