For example, a document on lung cancer can be indexed with the descriptors “lung” and “cancer”, regardless of the order of the terms.
The co-ordinating indexing was essentially developed by Mortimer Taube at the beginning of the 1950s and, due to the simple automatic processing, became popular in information retrieval ( UNITERM system). Although indexing in the same order is less precise than syntactic indexing , it is still used frequently, for example in many social tagging systems.
Export; Import; Italy; Germany; Wine; automobile
Problem: Because the relationships between the descriptors cannot be traced, the content of the document is unclear. The first part of the document can describe the export of cars to Italy and the second part the import of wine to Germany or vice versa. Syntactic indexing provides the solution to the problem .