Citation Analysis
Web of Science, Journal Citation Report
"Citations in the actual sense are common practice in scientific literature since the middle of the 19th century. Metaphorically speaking, the citation network of scientific articles is the glue that links publications with related content. The number of citations is seen as a direct measure for the (documented) resonance or the impact an article, a journal or a scientist has generated so far." Aus: The impact of Solid State Communications in view of the ISI Citation data. (1)
Concept | Problems | Journal Impact Factor | Impact Factor of specific Journals | analysed Journals | Hirsch-Index | Literature | Ask us
- The concept of citation analysis was developed in the late 1950's. The central tool is the database Science Citation Index (SCI), established by the Institute for Scientific Information (ISI), Philadelphia, USA, now part of the Thomson-Group. Its fundamental idea is to use publications of scientists and include references as an assessment criterion to evaluate the relevance of their scientific work.
- When working with figures from citation analysis these points are worth to consider:
| unique author? | incompletenesses and errors in reference lists |
| just the first author ? (old analyses) |
language barriers |
| negativ citations | temporal delays in the citation process |
| self citations | new research processes are recognized disproportionately late |
| citation cartels | age of the cited person |
| who is cited (prestige...) | amount of average citations heavily depends on the subject (differs by factor 5) See: "  Average citation rates of ISI-fields" (Source) |
| undocumented influences (acknowledgements, etc.) | majority of all publications is not cited at all, or only a few times |
- List of journals in ISI (SCI)- ISI: The Journal Selection Process
- Journal Impact Factor
| Calculation for 2000 S = number of artiles and reviews published 1998 and 1999 in certain journals (Source Items) R= number of citations in 2000 of all publications, that indicate the journals from "S" as source (References) R/S = Journal Impact Factor |
Impact factors of specific journal are available via JCR (Journal Citation Report). (GFZ only)
Worth considering when working with the JIF:
| covers the whole journal, indicator for „relative impact“ within a specific subject, comparison over different subjects is senseless, Factors: specific discipline, portion of methodical articles, portion of review articles, original language, time period of analysed data, everything said under "citation analysis" takes effect. |
| Hirsch-Index (h-Index): a newer way to calculate comparable numbers of citations of different authors: "The h-index is indicated by a green horizontal line in Web of Science. The number of items above this line, which is h, have at least h citations. For example, an h-index of 20 means that there are 20 items that have 20 citations or more." Developed by J.E. Hirsch and published in Proceedings of the National Academy of Sciences of the United States of America 102 (46): 16569-16572 November 15 2005. |
Literature:
- Recommendations for rankings in the system of higher education and research (Wissenschaftsrat)- Is it any good? Measuring scientific merit / P. Ball. ("Can there ever be a one-size-fitsall metric of the merit of one’s scientific output?")
- Scientography : Mapping the Tracks of Science, Impact Factor , Using the Impact Factor and The Agony and the Ecstasy - The History and the Meaning of the Journal Impact Factor articles from E. Garfield, the founder of ISI). - See also: History of Citation Indexing.
- Citation analysis: The counting house (Nature, 415, 726-729, 2002)
- Citation statistics: a report by the International Mathematical Union, the International Council of Industrial and Applied Mathematics, and the Institute of Mathematical Statistics (2008)
- Errors in citation statistics (Nature, 415, 101, 2002)
- Impactfactors
- Example for an analysis of a journal: The impact of Solid State Communications in view of the ISI Citation data.
more ...
Available in the library:
- Bibliometrische Verfahren und Methoden als Beitrag zur Trendbeobachtung und -erkennung / D. Tünger (2009). - M 09.0277 Item Status
- Citation analysis in research evaluation / H. Moed (2005). - N 05.0537 Item Status
- Analysis by ISI (incites):
10 most cited journals (2009)
10 most cited journals (2005)
25 most cited journals (2000)
Analysis of Geosciences (2005)
- Analysis of Environment/Ecology (2005)
- Journals Ranked by Impact: Ecology - Geology - Materials Science - Mineralogy - Oceanography - Meteorology & Atmospheric Sciences - Multidisciplinary Sciences - Paleontology - Forestry - Water Resources
- Science in Germany, 1996-2001 ;1998-2002; 1999-2003; 2001-2005, 2002-2006, 2003-2007, 2004-2008, 2005-2009, 2006-2010
- Top 20 Country Rankings in All Fields (2005)
- Meanwhile other providers adopted the idea of a citation index and have set up equivalent services. It will be exciting to follow their future developments, e.g.:
- Scopus (Elsevier, comparable with WoS).
- Google Scholar Citations (you need an account)
- Microsoft Academic search
Special features:
- Eigenfactor.org
- Citeseer
- SCImago Journal & Country Rank a portal on the basis of data from Scopus (Elsevier). The Google PageRank-Technology is used for the analysation of journals, here.
If you have any questions concerning citation analysis, feel free to contact us at any time.