Visualization problems in worldwide map portals

Abstract

Worldwide map portals have become an important platform for spatial data presentation. These portals attract millions of users every day and rank among the most visited Web sites in the world. For this reason, they have become a subject of study for cartographers carrying out research on problems in usability. This paper is based on previous usability studies that analysed Google Maps, MSN Maps & Directions, MapQuest and Multimap. The above-mentioned map portals have been evaluated from the following points of view: user interface, visualization, searching capabilities and help availability. Our contribution focuses primarily on visualization aspects of the previously-mentioned map portals, now designated as Google Maps, MapQuest and Bing Maps. In addition, functional aspects and map tools have been examined. Our main motivation was the rapid development of web cartography in general as well as improvements implemented on worldwide map portals in recent years. The visualization aspects were tested in a distributed web-based MUTEP (MUltivariate TEsting Program) environment and developed in cooperation with cartographers and psychologists at the Department of Geography at Masaryk University. The MUTEP application enables utilization of various testing methods. We decided to involve a combination of quantitative and qualitative information for the evaluation of map portal visualization aspects. Hypotheses for testing were based on a preliminary analysis of the differences among the map portals mentioned, e.g., differences in map content density, in the cartographic symbology employed or in generalization method. Results of the testing were subsequently statistically processed. Several usability tasks were conducted to discover the most significant current usability problems. So far, we have identified symbology, colour schemes, labelling and legibility problems as the crucial ones. These usability issues are further discussed in the paper and compared with previous studies. We hope this work will contribute to further improvement of worldwide map portals.