It basically measures the relationship between received citations and articles published in a journal. We can distinguish between expected impact factor and a factor in impact observed. Collaboration these indicators indicators measure the relations that have existed between scientific producers or agents and that ended with the joint publication of scientific results. They are based on data from authorship. The growth of science scientific literature obsolescence brings with it rigged a rapid aging of the scientific literature, i.e., there is a high tendency that scientific publications from falling into disuse with the passage of time. This is due to several causes: changes in the use of scientific literature over time: the information contained in the documents is valid but has been replaced by other more novel.Trend of scientific publications to fall into disuse: the information is valid but it has occurred in a field of knowledge of declining interest.Tendency of publications to reach its maximum level of citations shortly after being published, by what its frequency of use decreases rapidly with time.
Some of the factors that determine the ageing of the scientific literature at a very fast pace are for example, if the used literature handled ephemeral data, if they come in the form of reports or preliminary communications, or if they occur in areas of research that are advancing rapidly.There are indicators that measure the aging of publications. Burton and Kleber introduced the term half-life of scientific literature to refer to the period of time during which was posted half literature active circulating, meaning by this the amount of documents cited in a given time.The ISI and its databases. The Information Sciences Institute (ISI) of Philadelphia, created by Garfield, publishes and maintains a series of products that are used when performing Bibliometric studies.continue reading