CARTOGRAPHIC ANIMATION AND LEGENDS FOR TEMPORAL MAPS: EXPLORATION AND OR INTERACTION Menno-Jan Kraak #) , Rob Edsall &) and Alan M. MacEachren &) # ITC / Department of Geoinformatics P.O. Box 6 7500 AA Enschede the Netherlands +31 53 4874463 fax: +31 53 487433 kraak@itc.nl & 302 Walker Dept. of Geography The Pennsylvania State University University Park, PA 16802 +1 814 865 7491 fax: +1 814 863 7943 edsall@geog.psu.edu & alan@essc.psu.edu Abstract Temporal cartographic animations are increasingly common. For users to understand a temporal animation, they must not only apply an appropriate spatial knowledge schema that allows them to interpret relative geographic location, they must also apply an appropriate temporal schema that allows them to interpret meaning inherent in the sequence and pacing of the animation. Similar to static maps, then, the animated maps should be accompanied by a legend that prompts an appropriate schema. However, with animation, the legends function, not only as an interpretation devices but also as a navigation tools. This paper describes potential legends for temporal animation and argues that choices among them should be made with regard to the nature of the temporal data. A test is proposed to assess the viability of the different legends. Introduction In today’s world of spatial data handling, visualization requires an interactive and dynamic environment. The cartographic animation plays a prominent role here, and can be used not just to tell a story or explain a process, it can also reveal patterns or relations which would not be clear by looking at static maps. The cartographic animation is often categorised into temporal and non-temporal forms. The last is used to explain spatial relations by presenting individual map images in a logical sequence. The temporal animation is used to display world time in a temporal sequence, especially to display and explore the increasing varieties of spatio-temporal data sets becoming available. Temporal animation has some interesting advantages over traditional static temporal maps or map series. In particular, it offers 1 of 8 1/21/2002 12:56 PM This is a second draft, based on the earlier Penn State comments http://www.itc.nl/~kraak/legends