Information Retrieval System

An information retrieval (IR) system is (increasingly) a computer-based research tool. The purpose of IR systems is to provide references to pieces of information related to the particular inquiry. Traditional equivalents to IR systems include card catalogs and printed volumes of abstracts or annotated bibliographies. According to F. W. Lancaster, as quoted in the introduction to C. J. van Rijsbergen's Information Retrieval, “An information retrieval system does not inform (i.e., change the knowledge of) the user on the subject of his inquiry. It merely informs on the existence (or non-existence) and whereabouts of documents relating to his request” (van Rijsbergen, 1979, n.p.).

Information retrieval is a term with a long history and a changing meaning. In the past, an IR system was understood to be a closed information system that offered in-depth information on a very specific topic or area. The system usually included [Page 453]a mixture of complete documents, abstracts, and bibliographic references. The closest current example of that type of system in existence today is an information kiosk with no Internet access. With the arrival of the Internet, there are fewer closed systems, and increasingly documents are created using computer-based systems, so more documents are available online.

A conversational understanding of what is defined as information further compounds distinctions. Information retrieval scholars like van Rijsbergen make a distinction between data retrieval (DR) and IR. In the introduction to Information Retrieval, van Rijsbergen addressed the attributes that make the distinction relevant. Attributes particular to DR include exact matches, an artificial language used in queries, and sensitivity in error response. The attributes for IR, as expected, are the opposite. IR involves partial or best matches, natural language use in queries, and a lack of sensitivity in error responses.

A Web browser is an interesting example of a piece of software that is capable of handling both DR and IR queries. An example of data retrieval involves typing in a specific universal resource locator (URL), with the result that the specific page of information associated with that URL appears on screen. An artificial language is being used (the URL), which if not entered correctly, results in either the wrong information or no information at all (matching and error sensitivity). Still using the Web browser, information retrieval is represented by the use of a search engine (e.g., Google). Queries can be structured in natural language (What is the temperature of the sun?), with (at the time of this writing) 68,400,000 results. The order of the results, barring financial and other external considerations, is based on Google's proprietary software, ranking the results by partial and best matches based on content.