Knol, Onno M.Brandes, Laurens J.van der Maas, C. Wim M.Moeller, AndreasPage, BerndSchreiber, Martin2019-09-162019-09-162008https://dl.gi.de/handle/20.500.12116/26348The Shared Environmental Information System initiative (SEIS) is an important step in sharing environmental information. Experiences with two environmental information systems in the Netherlands, www.prtr.nl and www.milieuennatuurcompendium.nl, have provided insights which may contribute to the development of SEIS. The main question is how to provide the right type of information to the different user groups. A theoretical framework, the pyramid of hierarchical levels of information, is used to structure the different types of information (Figure 1). Each hierarchical level in data aggregation has its own target group. Some levels are less useful to a wider audience and it is questionable whether much effort has to be made to make this kind of information suitable for the group. It would be preferable a) to determine first what kind of information is suitable and needed for each target group and b) to provide each target group with its own information stream, despite the extra costs and efforts involved.Text/Conference Paper