Background knowledge and the construction of a situational representation from a diagram

Comprehension of a diagram requires viewers to construct from ifs graphic constituents a mental representation that captures the situational entities and relationships referred to by the diagram. However, this implies viewers possess appropriate background knowledge concerning the depicted situation, Meteorologists' and non-meteorologists' mental representations were investigated using a three-stage card sorting task during which subjects generated hierarchical groupings of the graphic elements of an Australian weather map diagram. Cluster analysis indicated that the two subject groups differed fundamentally in the basis of their sorting behavior. Subjects' justifications of the groupings suggested that non-meteorologists' mental representation of the diagram elements was primarily based upon domain-general, visuospatial characteristics whereas in meteorologists' representations, these characteristics were subservient to a domain-specific, situational interpretation of the graphic array, The findings indicate that background knowledge deficiencies may make it difficult for learners beginning study of a domain to construct suitable mental representations from domain-related diagrams.