The project aims at fostering our understanding of how the user experiences and copes with positional and thematic uncertainties in VGI-based map displays for wayfinding and navigation tasks. We will examine how landmark uncertainty affects wayfinding and pedestrian navigation performance of a user, and how cognitive principles and cartographic design can be used to overcome expected biases related to the characteristics of VGI data. Based on a series of experimental studies, empirical data (including eye-tracking data) will be collected for quantifying the bias introduced at the representational level due to landmark uncertainty. In addition, these studies will investigate the effectiveness of landmark signature design solutions based on MacEachren (1992) to control positional uncertainty. It can be assumed that in the context of map use related to wayfinding and navigation tasks, the visual implication of a landmark is most efficient when, besides its location, also its uncertainty is successfully conveyed. If the map user assumes that uncertainty is an inherent feature of a map then she/he is able to incorporate these implications when coping with incomplete or inaccurate maps. The project will examine whether maps can be designed in a way that suggests uncertainty to be represented implicitly. In consequence, the uncertainty present in the VGI data would be communicated to and thus made usable for the map reader. We expect to reveal that map users who adopt such a strategy for wayfinding tasks show higher flexibility in coping with thematic uncertainties and improved navigation performance. The findings of the proposed project will help improving our understanding of how characteristics of VGI data influence user interaction. Ultimately, this will contribute to enhancing VGI-based map design in future navigation applications.