A significant part of understanding how people use geographic information and technology concerns human cognition. This text provides an examination of the cognitive aspects of human-computer interaction for geographic information systems (GIS). Cognitive aspects are treated in relation to individual, group, behavioural, institutional and cultural perspectives. Extensions of GIS in the form of spatial decision support systems and SDSS for groups are part of the geographic information technology considered. The intended audience includes: geographic information users, systems analysts and system designers, and researchers in human-computer interaction.