Estimating the Number of Web Pages of the Environmental Administration in Germany

Abstract

The German environmental information portal PortalU 2 is an access point to a large number of information sources, all from public authorities. The user is offered a single point of entry for queries on a large variety of data with environmental relevance. In this respect, one of the most important tasks in the maintenance of the portal is to guarantee a high degree of relevance for all the different kinds of information sources. In addition to relevance, which often cannot be defined exactly, quantity of information is a measure that normaly can be obtained more easily. While this is generally true for highly structured information like records in a metadata catalogue or entities in database systems, it can be difficult when dealing with unstructured information sources like web pages. In this paper we show the obstacles that we encountered in our examinations on the size of our web page index and present how the information providers respectively contribute to the web page index of the environmental adminstration in Germany.