Measurement of the overlapping in three data bases with information on engineering

Abstract

The content of the databases usually varies so much in thematic diversity as in extension; some data bases cover specific information, whereas others are multidisciplinary. For that reason it is difficult to select as or as they stay or they eliminate of the collection of an information service, when economic factors take part or of another nature. The study of the overlapping and/or the cover of a series of data bases it corresponds to the field of informetrics. The results will be fundamental at the time of making a decision on the matter. The present work carries out a study of the overlapping and/or cover that present three data bases with contents in engineering (IEL, INSPEC and PASCAL). Similarity and overlapping indices were used (Jaccard and Meyer among others) to compare these three data bases. The results show a great difference between the data bases, as much in cover as in overlapping. INSPEC were the data base with greater cover (approximately 50% of documents and more of 50% of the sources) and an overlapping with the other data bases superior to 30%.