## 1 Introduction
Experience, gained from empirical studies, shows the value of participation in the decision-making process in various planning problems and spatial scales (local, regional, national/European _etc._) [23, 24, 25, 26, 27]. The _participatory planning approach_ is currently gaining importance in the light of the radical social, economic, cultural, environmental, technological, political, legislative and other developments and is closely relating to the demand of society for taking part in decision-making processes that have an impact on the management of resources. This demand is further reinforced by the symptoms of corruption and poor accounting of the political system [28, 29, 30] that are noticed in many countries of both the developed and the less developed world, where legislators, ministers, political parties _etc._ have in many occasions manipulated the public, while \"_...extracted illicit resources to maintain political power_\" [28] (p. 1236). In this respect, public participation is also largely reflecting the desire of the public for more transparent, accounting and democratic decision-making processes, leading to efficient, effective, legitimized and more valid governmental policy decisions [8, 31]. Furthermore, it better serves the _political nature_ of governmental decision-making, dealing with conflicting interests of various stakeholders' groups in policy making and implementation processes, while emphasizing representativeness, responsiveness and accountability of administrative agencies to the public [30], and seeking to compromise multiple goals emerging from these interests. Of importance, in such a context, is also the request for engaging, in the decision-making process, the less powerful groups of society, thus ensuring equal access to decision-making processes and resource management by all societal groups. Until recently, the so-called \"_traditional public participation_\" _methods_ were the only means through which public participation could take place. The advent of _Web and Web 2.0_ though, has set the ground for broadening the chances for participation, through the exploitation of Internet and available \"_e-tools_\" [32]. According to [PERSON] _et al._[33] (pp. 907, 918), \"_...the proliferation of the Internet...has provided many opportunities to disseminate public information and also the on-line systems have the potential to involve the public more closely in the planning process_\"; while [PERSON] [34] (p. 117) states that \"_... the use of these specific technologies has helped users to exchange and share information not only from personal computers, but also through mobile appliances, such as smart phones and pads_\". From the governmental point of view, Internet technologies enabled the establishment of \"e-governance\" collaborative activities through \"Government 2.0\" platforms [35]. Such activities assure transparency of governmental operations and enhance the range and level of public participation [32]. The _choice_ of Web-based or traditional participatory tools draws upon the pros and cons of each specific approach and the specific problem at hand. Compared to traditional, Web-based participatory tools can offer some significant _advantages_, mainly referring to [32]:* Time- and space-independence;
* Engagement of a large diversity of potential participants;
* Enhancement of democracy and transparency aspects;
* Wider diffusion of knowledge and information, rendering thus the Web-based participatory approaches powerful tools for \"increasing awareness\";
* Less time-consuming to implement e-participatory exercises;
* Anonymity, enhancing participants' potential to freely express their views. Nevertheless critical issues, such as the _digital divide_ and the disadvantageous position of those having _no access_ to computers and ICTs infrastructure or lacking the necessary ICTs skills, should be taken into consideration [36, 37]. These can, by their nature, lead to a certain kind of social inequality and social exclusion [33] in the participatory context.