followed by Cora, which focused primarily on the field of computer science and information science. These were later followed by large scale academic domain citation systems such as the Google Scholar and Microsoft Academic. Such autonomous citation indexing is not yet perfect in citation extraction or citation clustering with an error rate estimated by some at 10% though a careful statistical sampling has yet to be done. This has resulted in such authors as Ann Arbor, Milton Keynes, and Walton Hall being credited with extensive academic output. SCI claims to create automatic citation indexing through purely programmatic methods. Even the older records have a similar magnitude of error. Citation impact Citation analysis for legal documents Citation analysis for legal documents is an approach to facilitate the understanding and analysis of inter-related regulatory compliance documents by exploration of the citations that connect provisions to other provisions within the same document or between different documents. Citation analysis uses a citation graph extracted from a regulatory document, which could supplement E-discovery - a process that leverages on technological innovations in big data analytics. Controversies E-publishing: due to the unprecedented growth of electronic resource (e-resource) availability, one of the questions currently being explored is, "how often are e-resources being cited in my field?" For instance, there are claims that On-Line access to computer science literature leads to higher citation rates, however, humanities articles may suffer if not in print. Self-citations: it has been criticized that authors game the system by accumulating citations by citing themselves excessively. For instance, it has been found that men tend to cite themselves more often than women. Citation pollution: the infiltration of retracted research, or fake research, being cited in legitimate research, but negatively impacting on the validity of the research. It is due to various factors, including the publication race and the concerning rise in unscrupulous business practices related to so-called predatory or deceptive publishers, research quality, in general, is facing different types of threats. See also Google economy Journalology Main path analysis San Francisco Declaration on Research Assessment Notes References Analysis Citation metrics