Remember the User Four lessons on usability and the GeoWeb By Brian Noyle and David Bouwman, DTSAgile The Geospatial Web or GeoWeb is the current darling of location-based technologies and neogeography. As a community, geodevelopers are moving away from exposing lots of complex GIS functionality in the Web browser. The GeoWeb is high-performance maps, mashups, distributed data, game-style navigation, and communal- or user-generated geospatial content. In essence, it is all things Web 2.0 in a map. For Esri customers, it is REST, JavaScript, Flex, and Silverlight APIs for ArcGIS Server. Of late, Esri has been evangelizing on the topic of high-performance Web maps through online training offerings such as Authoring and Deploying Fast Web Maps (training.esri.com/ acb2000/showdetl.cfm?DID=6&Product_ ID=943) and articles such as "Five Steps to Better Performance" (www.esri.com/news/ arcuser/0609/files/5forfastmaps.pdf) in the Summer 2009 issue of ArcUser. While quick performance and a killer site skin with an open, uncluttered layout are certainly important in the age of the GeoWeb, they are only part of the equation. Geodevelopers are still challenged on the usability front because the typical application with buckets of data, loads of tools, and an unconstrained workflow is still making it into the market in many cases. Creating great apps for publicfacing or line-of-business sites serving nonGIS professionals requires focusing on the user and a mental model of how the user interacts with the functionality that the geodeveloper exposes. These four lessons will help a geodeveloper do this. Lesson 1: Always Hide the Details A forester knows trees. A state trooper knows law enforcement. A county auditor knows real estate assessment. However, none of these users is likely to know much about buffer, intersect, or union operations or Thiessen polygons. When a roadway project manager asks for all structures near her project (without knowing it), she is really asking to locate point features in the Structures layer that fall within one mile of the section of Route 6A between mile26 ArcUser Fall 2009 Figure 1: Hide multi-GIS operation functions behind simple interface elements. This eliminates user-facing complexity and provides the opportunity for performance gains in the implementation. posts 12 and 25. A GIS professional knows that getting this information requires an initial point selection, followed by a buffer, an intersection with a second layer (roads), followed by a buffer of the resulting road segment, followed by an intersection of the second buffer with the structures layer. The roadway project manager does not know this and she shouldn't need to know this. Consider the application shown in Figure 1. It serves data via the Web Map Service (WMS) capabilities of ArcGIS Server 9.2. Note the minimalist map navigation at the top left of the map and the conspicuous lack of multiple tool buttons, menus, legends, and layer lists. This application is used by state Department of Transportation roadway project managers. To do their job, all these folks need to do is specify what road segment a project is on and list structures along the road (culverts, mast arms) that are impacted by a project. Highly usable systems hide complex GIS operations from the user and get the desired answer quickly. The selection, buffers, and intersections that get the roadway manager the information she needs to do her job are hidden inconspicuously behind the Search for Structures button in Figure 1. Once the project road segment is selected, this search button becomes enabled. A single click returns a list of affected structures to the user in approximately 0.3 second, allowing her to get back to what's really important. www.esri.com