Evaluating Decision Support Systems for PPGIS Applications

Article excerpt

Graeme Aggett and Chris McColl


Involving the public during the development of alternative land-use scenarios leads to a more sustainable, legitimate, and democratic decision-making process and more effective land-use plans (Abbot et al. 1998; Al-Kodmany 2001). Geographic information systems (GIS) have been found effective in the facilitation of continuous public participation by providing an opportunity for citizens to contribute complementary knowledge, review technical data, visualize development proposals, and subjectively test the validity of assumptions that underpin many spatial planning decisions (Forrester et al. 1999; Al-Kodmany 2001; Ventura et al. 2002). The inclusion of GIS technology in decision-making processes as a tool to engage, blend public knowledge and concerns with expert information, and ultimately empower citizens, has developed into a broad body of research generally referred to as public participatory geographic information systems (PPGIS) (Nyerges et al. 1997; Harris and Weiner 1998; King 2002).

The PPGIS research has closely examined the social implications that may arise due to the application of GIS technology to decision-making processes involving marginalized communities (Obermeyer 1998; Craig et al. 2002; Warren 2004). Cautionary issues have arisen noting the negative impacts PPGIS could have upon differentiated social groups within communities. For example, inequitable access to the information, technology, and expertise of GIS could potentially disadvantage the ability of small or less wealthy groups to fully engage in decision-making processes where spatial analyses have been used to validate decisions (Harris and Weiner 1998; Elwood and Ghose 2001; Ghose 2003).

Additionally, PPGIS research has focused considerable attention to applying PPGIS frameworks that can more effectively engage and empower citizens during the public decision-making process (Elwood and Ghose 9001; Kyem 2001; Sedogo and Groten 9002). However, existing GIS technologies used within public participatory contexts have limited abilities to support decision-making processes due to a lack of system transparency, the need for expert training, the cost of hardware/ software, limited visualization capabilities, and inaccessibility of required data (Barndt 1998; Elwood and Leitner 1998; Al-Kodmany 2001). To address these short-comings, modified GIS tools have been developed to support successful PPGIS applications for democratic decision making. Several terms are used to describe these modified geographical information and communication technologies, such as spatial decision support systems (SDSS); decision support systems (DSS); and in some instances, planning support systems (PSS) (Jankowski and Nyerges 2001; Klosterman 2001; Geertman 2002). Herein we refer to these systems collectively as DSS instruments.

Increasingly, DSS are tightly coupled with, and/or developed upon, GIS platforms to better address the spatial decision-making processes of local governments and communities, and to support growing numbers of PPGIS practitioners (Brail 2001; Geertman 2002). Decision support system development has focused on integrating the analytical capabilities of GIS, including improved visualization technology, which operates within a "real-time" format to promote and support public debate (Shifter 1998; Jankowski and Nyerges 2001; Geertman 2002). These modified GIS instruments are developed with the intention of creating systems that are more transparent to users rather than the so-called "black box" systems, a label GIS has often fallen prey to (Klosterman 2001; Drew 2003).

Attempts have been made to design DSS to be easily understood and operated by users and flexible in application. Superior graphic and visualization capabilities have been incorporated to promote clearer communication of ideas (Al-Kodmany 2001; Geertman 2002; Haklay and Tobon 2003). These rapid advances have raised many questions regarding the development of new DSS and their ability to support PPGIS applications, including the following:

* How effective are emerging DSS at supporting various stages of participatory decision making, not only in terms of functionality hut also utility? …