Comparative evaluation of chemical and environmental online and CD-ROM databases

In a constantly expanding world of chemical and environmental information s ources, the need for their evaluation gains more and more importance. This paper presents a comparative evaluation of datasources of online databases and databases on CD-ROM (called CD-ROMs in this paper) in the field of envi ronmental chemicals. The approach is based on research results gained in th e years 1996/1997. The authors sue aware that changes in the database indus try may lead to different results. Before the actual evaluation process can be carried out, two major procedures are necessary, namely, the selection of sets of datasources and the definition of evaluation criteria. In order to perform the difficult task of an evaluation based on several criteria, a general order relation has to be introduced. Methods of partially ordered set theory are applied, and the results are visualized by the technique of Hasse diagrams. On the basis of these evaluation results, the datasources a re grouped and then evaluated. It will be shown that there are groups of da tasources with quite specific property profiles, and only two groups turn o ut to be relatively better than the others.