“Fast, intuitive, informative, fast”, according to Brian Timoney [1], these requirements are the secret of good web mapping applications. Ok, great, but how to handle 200 layers, permalinks, tooltips, address search, feature search, catalogs, layer trees, KML, GPX, measurements, profile, print, help, feedback, copyrights, contextual menu etc, etc.. ? This presentation will try to provide an answer based on the experiences made by the map.geo.admin.ch geoportal. “User centered design” is probably the most important process in order to propose an usable geoportal. This process implies to identify the personas (or the user types) and to identify the use cases accomplished by these users. For map.geo.admin.ch, several methods have been used: contextual inquiry, user survey, analysis of user feedbacks and user tests. This talk will present these various methods and discuss their key findings: - A geoportal is not a GIS application. The UI has to be as simple as simple with only the strictly required features. - The pareto rule “80% of the effects come from 20% of the cause” applies perfectly for the features of a geoportal. The majority of features are “only” expert features. - Search has to be fast, efficient, fast, efficient, fast, efficient etc... The majority of users are used to work with Google search. The geoportal has to offer equivalent possibilities. - Thematic geoportals are easier to use. The diversity of layers is a killer for a geoportal. Layers need to be contextualized and grouped. - No need to have an “i” button is order to get attributive information. If the users wants an information about a feature, he has simply to click on this feature. - “Settings” are forbidden (because never used) - Users are able to navigate in the map with the mouse... and this is the first thing users do after starting the application. - The switch between mobile and desktop worlds has to be possible without losing information. Internet users expect to work with a geoportal like with other web applications. The same design patterns have to be used in order to simplify the access to the geoinformation and to make your geoportal used and useful. Let’s see if this dream can be a reality ! [1] http://mapbrief.com/2013/02/11/the-tyranny-of-requirements-why-map-portals-dont-work-part-iii/