US information retrieval system evolution and evaluation (1945-1975)

Information retrieval has evolved through four phases: manual and mechanical devices; off line computing; online computing and vendor access; and distributed, networked, and mass computing. The article primarily addresses the first three phases. We examine IR systems in terms of four basic functions within a broader communications system context: analysis of document information content including description of document elements (such as author, title, volume, and so on), abstracting, indexing, and other processes; identification and location of sources of documents through bibliographic browsing and searching; evaluation and assessment of bibliographic search output such as screening of bibliographic descriptions; and provision of physical access to document information content through various media such as print on paper, microform, and screen displays.