Relating distortion to performance in distortion oriented displays

Distortion oriented displays (DOD) are an interface approach for supporting navigation through large visual datasets (maps) whilst avoiding loss of context. DOD present the user with a movable virtual magnifying glass within which a detailed view of the point of focus is presented. Surrounding this the rest of the map is presented in a visually compressed view to ensure context is retained. The large quantity of data, spatial expansiveness and range of data sizes found in demanding applications produce two major performance problems for DOD; dynamic response and high magnification requirements. Fast dynamic response is an important feature of DOD; the user should be able to move the point of focus around the screen and experience no discernible delay in the redisplay of the map. Therefore computational overhead is very important when considering the use of a DOD for visualisations of large datasets. Screen size restrictions and the expansive and physically diverse nature of the data mean high magnification is needed to view the required level of detail in the focal region. This can produce unacceptable distortions in the context region for some types of DOD. This paper considers how distortion can affect DOD performance and how understanding this can help produce DOD with higher useable magnification factors and better dynamic response.