By selection, stacking, assembly and analysis, the user may discover that seemingly unrelated topic data actually have some form of spatial relation. In the era of traditional paper maps, this was a time-consuming effort, but today it can be accomplished with staggering speed and efficiency with the aid of GIS.
透過這種單項抽離、套疊、重組、分析，使用者可能就會發現原先看似各自孤立的主題訊息，其實具有某種空間上的關連性；這在傳統紙地圖時代是十分耗時費力的事，如今在 GIS 幫助下，可以快速準確地完成，其效率判若雲泥。