Application of Eye-tracking in Cartography

W artykule omówiono okulografię (eye-tracking) jako technikę badawczą wykorzystywaną w kartografii. Przedstawiono jej założenia, stosowane rozwiązania sprzętowe oraz zarysowano historię jej wykorzystania w różnych dyscyplinach, koncentrując się na badaniach z zakresu użytkowania map. Zaakcentowano najważniejsze wyzwania badawcze stojące przed kartografami pragnącymi ją wykorzystać.Eye-tracking is a group of various techniques in which eye movements are recorded usually in order to get information about the path composed of gaze points. Eye-tracking used to be a unusual technique, mainly because of lack of suitable equipment. Currently eye-tracking has become more available because the cost has become Iower and it is not as time-consuming. Eye-tracking has become the focus of attention of psychology, medicine and ergonomics. It is also used in market research and research projects on HCI Human - Computer Interaction. Eye--tracking is also used by cartographers. While reading a map, the part we concentrate our attention on is most effectively analyzed, i.e. the part whose image is located in the fovea centralis during fixation. The image changes together with saccades (fast eye movements) when we focus our attention on other parts of the map. Through employing the eye--tracking technique we can follow the cognitive proc-ess accompanying map reading. It can be determined for instance what catches the reader's attention first, what is the sequence of viewing the elements of map content, when the reader looks at the legend, etc. Although first attempts at using the eye-tracking technique in cartography go back to 1970s cartographers lost interest in it later on. However, at the beginning of the new millennium a rise in the amount of publications can be noted. The generał aim of doing research with the eye--tracking technique is to get deeper insight into how maps are used, e.g. indicate typical visual behaviors. Sometimes, the goal is to find out about behavior during visual searching of information on a map. An interesting approach connected to behavior is research in which the main goal is to recognize differences between the visual behavior of professional map users and the visual behavior of amateurs. It is not easy to specify if the results of eye-tracking research can be used in map design or whether they discover anything new. It is certain however that using the technique in research can shed new light on popu-lar opinions thus providing a strong scientific basis for arguments or strengthen knowledge. In cartography eye-tracking can be especially used in research on interactive maps, their usage advantages and interface designing. Sometimes the aim of research is to compare cartographic elaborations of similar content and functionality but different graphic form and distribution of interactive interface elements. In the development of cartography, research with the use of eye-tracking has arranged, verified and set-tled knowledge. What used to be only assumed (especially when we were interested in the behavior during visual map analysis) can now be verified using eye--tracking. Despite the progress in the technique of eye-tracking and its usage in cartography, many problems still need to be looked into. An important issue is the difficulty of interpreting the information about visual map analysis behavior. Thanks to eye-tracking we are able to determine which parts of a map are looked at, but it is still hard to indicate factors conditioning this behavior. Database (BDO) is presented for both systems in the form of a sequence of generalization activities and respective operators and generalization algorithms. Thus prepared database has been verified by a series of research experiments covering settiement generalization and road network in Lower Silesian and Łódź voivodships. In order to adapt the generalization process to the requirements of smali scale publications new tools and algorithms have been designed or modified for the systems, which improves correctness of generalization of particular thematic layers