LIS618 lecture 6 Thomas Krichel

Structure of talk course evaluations OCLC firstsearch citation indexing and searching scirus

citation indexing is a technique that can be used if there on documents that cite other documents –scientific papers –patents –legal documents pioneered by Shepherd's citation index to case law since 1870s

citation vs word indexing word indexing as severe limitations –different authors use different words –language evolves, e.g. euphenics –controlled vocabularies can help but reduce the subject to the categories are subject to human error in contrast citation indexing appears more mechanical and thus objective

citation quality good citation data is a sign of good scholarship good citation data –has all relevant papers cited to show that the authors are aware of related literature –citation has to conform to journal style but citation styles vary a lot for disciplines citations in the hard sciences are a lot more formal

citation indexes to scientific papers essentially pioneered by Eugene Garfield chemical citation index in the late 50s index of genetics in the early 60s ISI issued an interdisciplinary science citation index in the 60s Extended to social science citation index and arts and humanities citation index virtual monopoly

what sources to index Bradford's law would imply that it takes 500 to 1000 journals to cover the literature that is essential to a discipline Garfield's law of concentration says that the tail end of one discipline is core in another discipline. In SCI, mid 70s data –50% of all citations are in 250 journals –75% of all citations are in 1000 journals –84% of all citations are in 2000 journals

impact factor is the rate of citations that articles in a journal receive divided by the number of articles that a journal publisher has become over time a crucial indicator of journal quality given the ISI a monopoly position in the evaluation of journal quality

citation index for a year NAIR KG 66 BIOCHEMESTRY5 150 DESOUSA RCJ PHYSL PAR R71575 MASLINSK. CAGENT ACTION … 68 CIRCULATION RESEARCH 23 ANVERSA PLAB INV …

Source index LUTZ H RETTENMA.G (DE) ULTRASONIC DIAGNOSIS OF RENAL DESEASE DEUT MED WO RN8 there is also a patent index

type of searches citation verification – uses source index only eponymic search methodology search follow-up searches review searches precise question searches exhaustive bibliographies

usefulness of citation indexing subject categorization is –more precise –more stable –more flexible –more detailed reveals links between old and new papers draws our attention to events that have happened

most successful application google uses graph structure of web links to distinguish between important and not important pages. pages that have many links to them by important pages are deemed to be important.