“…An investigation of the scientific literature concerning geoinformation technology, planning and PSS in particular shows several landmark studies from the 1990s that attempt to integrate GIS querying with both sketching and a hardware interface that supports groupwork (Blaser et al, 2000;Shiffer, 1992;Singh, 1999). In studies that followed at later dates, three major lines of research can be distinguished: (1) the integration of sketching with GIS, among others, through shape-recognition in GIS environments (Sun et al, 2003;Zhengxing et al, 2005); (2) the development of innovative hardware interfaces that connect GIS and sketching to a group setting (Hopkins et al, 2004); and (3) the effective application of the PSS that combine these functions (Geertman, 2002;Harris, 2001;Sieber, 2006).…”