Reliable 2D Crowdsourced Cadastral Surveys: Case Studies from Greece and Romania This paper is part of a doctoral dissertation (PhD) research that investigates the development of a procedure for reliable 2D crowdsourced cadastral surveying introducing the use of new Information Technology IT tools and increased citizen participation, supported by mservices. For the development of this procedure, the formal cadastral procedure applied currently in two Europeans countries, Greece and Romania, for their modern nationwide projects is firstly investigated. The first part of this paper briefly investigates the current stage of progress of those projects in both countries, as well as the specifications and procedures applied for the cadastral surveys, and assesses the level of participation of the right holders and the efficiency of the current procedures. Then, a proposal for a crowdsourced general procedure with increased participation of the right holders in the initial cadastral data collection phase is designed that it may be of value either for the planners of those two projects to improve their projects towards a more fitforpurpose approach and successfully meet the deadlines timely, or for researchers and planners of other projects with similar nationwide approaches which also require accurate, assured and authoritative end products. For the assessment of the applicability of the proposal, three case studies are held and tested in urban, rural and suburban areas in both countries, using both a commercial application and an open source one. These crowdsourced surveys are compared to the formal cadastral surveys that have been compiled by cadastral professionals in both countries and the achieved results are assessed and judged as satisfactory in terms of geometric accuracies and the avoidance of gross errors in the location of the parcels. A proposal for future research in order to further improve the proposed procedure is discussed.

Volunteered multidimensional design to the test: the farmland biodiversity VGI4Bio Projects experiment. Moving volunteers of VGI (Volunteer Geographic Information) from passive data producers to active data analysts in the context of Data Warehouses (DWs) and OLAP systems is an open issue. Indeed, volunteers have particular features that make existing DW design methodologies inadequate. In this paper, using a real case study concerning the farmland biodiversity, we test the methodology proposed in 5, which enables volunteers to design DW schemes. The experiments aim at answering two research questions: (i)How can volunteered design be streamlined with respect to the methodology described in 5?; (ii)To what extent does the involvement of a large number of volunteers actually improve the cubes implemented? Our experiments confirm the adequacy of the methodology proposed in 5, but they also reveal some important limitations. Among them, we identify possible conflicts among volunteers in the first steps of the design process. To address this issue we propose a solution based on social software engineering tools, and in particular Wiki systems.