Spatial-Query-by-Sketch

Today´s methods for interacting with geographic information systems (GISs) and geographic databases are primarily aspatial, as they require users to deal with geographic data primarily through alphanumeric command languages. Spatial querying by typing a command in some spatial query language or by selecting the same syntax from pull-down menus is a tedious process, because it often requires extensive training in the use of the particular query language, and forces users to translate a spatial image they may have in their mind into a non-spatial language. To overcome this conceptual gap, we propose Spatial-Query-by-Sketch, a sketch-based GIS user interface that focuses on specifying spatial relations by drawing them. This query style more directly supports human spatial thinking, which is critical because users frequently have an image-like representation in their minds when they query about spatial configurations. This paper introduces the fundamental concepts of Spatial-Query-by-Sketch, provides examples of typical interactions and discusses query processing strategies by relaxing the constraints drawn in terms of a qualitative model