Our research is part of a broader research study towards an education model for understanding of informatics systems at upper secondary level. There are three characteristics specific to informatics systems: their observable behaviour, their internal structure, and implementation aspects. Informatics systems represent networked fundamental ideas of informatics. Thus, networking these concepts within a mental model is essential to understand informatics systems. Observation exercises and systematic exploration have been identified as a means to overcome the cognitive barrier build by complex informatics systems.