Recuperación de la información
Information retrieval methods. The object of any filing or storage system is to make available at later date the information in the documents stored. Each collection will have its own special requirements and any system which meets those requirements will be an adequate retrieval system for that collection. If the number of documents in the system is very small, no formal retrieval system is required. It will be possible and adequate to scan all the documents. As further documents are added this soon becomes impossible and some means must be adopted for speeding up the search. The collection may now be divided into two parts, the documents themselves and an index to them. If a reference to the documents is placed in each appropriate place in the index, an information retrieval system has been created. The simplest system is a card index in which there in a separate card for each entry. The cards may be arranged either in a single or in a number of alphabetical sequences, which has the effect of scattering material on allied subjects, or in a classified order. The number of cards in such a system soon becomes large, and the labour of making the separate entries is great, so that either some desirable entries will not be made, so that information cannot be retrieved, or the index will become too cumbersome for easy use, and information in the collection will be ‘lost.’ Some easier and more effective method is needed.
If references to (or abstracts of) the documents are written on marginal punched cards (I), and these cards are notched to show all relevant headings a search for information on a number of headings, a search for information on a number of headings simultaneously becomes simplified, and the labour of maintaining the index is lessened. One position on the cards may be allotted to each possible subject heading and this is notched to show the presence of that characteristic in the document. The cards have only a limited number of holes, so that the number of headings can easily be greater than the available holes. There are several types of coding system which can be used to increase the capacity.
Subjects may be allotted numbers on a serial or classified basis, and these numbers be used in place of the subject heading on the cards either by allotting a separate set of holes to each digit or by use of a numerical code. Each type of heading may be punched into an appropriate field. Alternatively, the whole space on the card may be made into a single field and the codes for different subject headings be punched one over the other. This superposition of codes is most effective if the code combinations are chosen on a mathematically random basis. The number of false combinations which will be generated by interference between codes can be precisely calculated, and kept to an acceptably low proportion, by proper design of the system.
If the collection is large enough, machine sorted punched cards may be justifiable. Code numbers for the appropriate fields in the body of the card, and searching can quickly be done by machine. Even with high speeds of search, the time taken to answer a question may be unacceptably high unless care is taken to subdivide the index file so that only a portion of it has to be searched for any query. If the load on the sorter is high enough to make the system economic, the waiting time may make the overall search time longer than for simpler and cheaper systems.
Landau, Thomas. 1967. Encyclopaedia of Librarianship. London: Bowes & Bowes. Pág. 222
Information retrieval. Finding documents or the information contained in documents in a library or other collection, selectively recalling recorded information. Methods of retrieval vary from a simple index or catalogue to the documents, to some kind of punched card or microfilm record which requires large or expensive equipment form mechanically selecting the material required. Classification, indexing and machine searching are all systems of information retrieval.
Montague, Leonard. 1971. The librarians’ glossary of terms used in librarianship and the book crafts and reference book. Great Britain: The trinity press. Pág. 329
An Information retrieval (IR) system comprises the people, activities and equipment concerned with the acquisition, organization and retrieval of information. Discussion of IR usually assumes that an IR system is computer-based. Whilst this is increasingly the case, IR systems can be manual, and the definition given here would include all manually searched library catalogues as well as bibliographies, indexes and abstracting publications. Nevertheless, IR more commonly means retrieval from a computer system, whether the information is held on a local system, increasingly in CD-ROM form, or on a remote system accessed by a telecommunications network. The requires put to IR systems are one of two types: the search is either for a known item or for items in a particular subject.
In responding to requires, IR systems must achieve a balance between speed, accuracy, cost and retrieval effectiveness in revealing the existence of information items and displaying surrogates (representations) or the original items. The effective of retrieval is measured by the pair of measures recall ratio and precision ratio. The recall ratio measures the proportion of those relevant documents in a database which are retrieved, whilst the precision ratio measures the proportion of the retrieved items which are relevant. There has been since the late 1950s which has stablished that the two measures are inversely proportional. In general, steps taken to improve one measure of performance will have a deleterious effect on the other measure.
Feather, John; Sturges, Paul. 1997. International encyclopedia of information and library science. Great Britain: Routledge. Pág. 211
Proceso por el cual se accede a una información que ha sido previamente almacenada. Disciplina científica que estudia los procedimientos y técnicas de representación, ordenación, búsqueda, presentación y evaluación de la información en sistemas automatizados, con el objetivo de facilitar el acceso eficaz y eficientemente a la misma. Se trata de un ámbito científico de carácter interdisciplinar, que forma parte de la informática y que incluye la gestión de bases de datos y en general de objetos. Tradicionalmente, se ha ocupado de las estructuras de almacenamiento, métodos de indización, lenguajes de interrogación, estrategias de búsqueda, visualización de datos y evaluación de la recuperación. En la actualidad, el campo ha revolucionado con la incorporación de los documentos multimedia, los nuevos métodos de recuperación de información –basados en la clasificación automática, en la utilización de lenguajes de marcado de documentos, en la aplicación de sistemas expertos y de procedimientos de retroalimentación por relevancia y en la hipermedia- y los sistemas de visualización gráfica. Recuperación de la información es una apócope (supresión) del término más amplio “tratamiento y recuperación de la información”, una traducción libre en español del término anglosajón “information storage and retrieval”. A veces se utiliza conjuntamente con el término procesamiento de la informacion para abarcar prácticamente todo el campo de la informática lógica (information retrieval and processing).
López, José. 2004. Diccionario enciclopédico de ciencias de la documentación. España: Editorial Síntesis. Pág. 371
La Recuperación de Información (RI) no es un área nueva, sino que se viene desarrollando desde finales de la década de 1950. Sin embargo, en la actualidad adquiere un rol más importante debido al valor que tiene la información. Se puede plantear que disponer o no de la información justa en tiempo y forma puede resultar en el éxito o fracaso de una operación. De aquí, la importancia de los Sistemas de Recuperación de Información (SRI) que pueden manejar – con ciertas limitaciones – estas situaciones de manera eficaz y eficiente.
Tolosa, Gabriel; Bordignon, Fernando. 2007. Introducción a la recuperación de información: conceptos, modelos y algoritmos básicos. Argentina: Universidad Nacional de Luján. Pág. 9
