Visual search in graphical interfaces: a user psychological approach:Dissertation

This dissertation applies and develops a user psychological approach to the research of human-computer interaction (HCI). The motivation behind the approach is to derive scientific psychological knowledge to explain and solve practical problems in HCI. Psychology provides data and theories to build explanatory frameworks, within which the user behavior during interaction tasks can be described and analyzed. In this dissertation, the particular explanatory framework is derived from cognitive psychology. Understanding of cognitive functions of the user is used to explain certain phenomena when the user interacts with a computer. A specific problem, to which the user cognitive psychology approach is applied, is the spatial arrangement of interface objects in graphical interfaces. Spatial arrangement of objects has been suggested to have substantial consequences on user behavior, but empirically the issue is understudied. To assess the problem of spatial arrangement, a cognitive model of visual search is constructed on the basis of cognitive psychology theories and findings. Four experimental studies assess the influences of spatial arrangement on visual search. The results of the studies show that the cognitive model explains the effects of spatial arrangement on visual search at the level of underlying cognitive functions. The results are also used to revise the model. It is argued that the model provides useful information for graphical interface designers in respect to visual search. The dissertation also evaluates the feasibility of the user cognitive psychology approach. It is shown that it is possible to apply psychological knowledge to profoundly explain practical problems within human-computer interaction. This is increasingly important as the computerized environments, and consequently, interaction problems, are becoming more and more complex in everyday life. The dissertation suggests, however, that more integrative research approaches motivated by real-world problems is needed to be carried out in cognitive psychology to increase its feasibility for HCI research