An information system is an organisation of people, materials and machines that serves to facilitate the transfer of information from one person to a… - Brian Campbell Vickery

History presents a series of cultural epochs. Each is a span of years within which knowledge presents a more or less unified structure which can be expressed in a classification, but each new epoch requires a new classification.

Neither citation nor loan demand is an adequate measure of literature use by a large community. Each is only an indicator, illuminating some aspects of use but with its own inherent bias. The joint study of several indicators gives a more balanced picture..

The representation of knowledge in symbolic form is a matter that has pre-occupied the world of documentation since its origin. The problem is now relevant in many situations other than documents and indexes. The structure of records and files in databases: data structures in computer programming; the syntactic and semantic structure of natural language; knowledge representation in artificial intelligence; models of human memory: in all these fields it is necessary to decide how knowledge may be represented so that the representations may be manipulated.