STIMULATE 5 Ronald Rousseau Web page: users.telenet.be/ronald.rousseau

Citation analysis Advanced parts Bibliographic coupling Co-citation Citation context analysis The Journal Citation Reports (JCR) Bibliometric indicators

Bibliographic coupling and co-citation

Co-citation network

Co-citation measures

Citation context analysis Cited documents become symbols for the ideas they contain. Highly cited documents can be considered as exemplars or concept symbols: illustrations of methods or theories which comprise the essential repertoire of techniques in a specialty.

Citation analysis of scientific journals The Journal Citation Reports (JCR) The annual publication of the JCR by ISI (nowadays Thomson-ISI) has led to a whole series of indicators. Of these the journal impact factor is the best known.

The publication – citation table Publ year # Publ # cit rec’d in # cit rec’d in # cit rec’d in # cit rec’d in # cit rec’d in

The ISI impact factor (synchronous) Publ year # Publ # cit rec’d in IF(2003) = # cit rec’d in (20+12)/ (35+40) # cit rec’d in =0.427 # cit rec’d in # cit rec’d in

Mathematical formulas: the general synchronous impact factor (Rousseau, 1988) CIT(Y-2,Y) + CIT(Y-1,Y) IF(Y)= = IF 2 (Y) PUB(Y-2) + PUB(Y-1)

Diachronous impact factors Publ year # Publ # cit rec’d in DIF 3 (2002) = # cit rec’d in ( ) / 40 # cit rec’d in = # cit rec’d in # cit rec’d in

Mathematical formulas: the general diachronous impact factor

The source – item table Period of origin Period 1Period 2Period 3Period 4Period 5 # sources # items period 1 5 # items period # items period # items period # items period

Examples of general source-item relations Scientific journal  (publishes) articles  (receives) citations Scientific journal  (publishes) issues  (receives) citations Scientific journal  (publishes) one particular issue  (receives) citations Congress proceedings  (consists of) articles  (receives) citations Institute  (publishes) webpages  (receives) inlinks (the institute web impact factor) Country  (publishes) webpages  (receives) inlinks (from other countries) (country web impact factor) Fiction author  (writes/publishes) books  (realizes) sales Country  (publishes) articles in a particular domain  (receives) citations Journal  (publishes) articles  (receives) citations in one particular journal

Generalized impact factors (Frandsen – Rousseau) Publ year # Publ # cit rec’d in # cit rec’d in # cit rec’d in # cit rec’d in # cit rec’d in

The median impact factor (MIF): a new impact indicator Here TOT denotes the total number of citations received by journal J in the year Y. CPUB(Y-X,Y) denotes the cumulative number of publications in the journal J, during the period [Y-X, Y]. The symbol X denotes the median cited age.

References SOMBATSOMPOP, N., MARKPIN, T., PREMKAMOLNETR, N. (2004), A modified method for calculating the impact factors of journals in ISI Journal Citation Reports: polymer science category in Scientometrics, 60: ROUSSEAU, R. (2005), Median and percentile impact factors: a set of new indicators. Scientometrics, 63:

Example: Scientometrics MIF(2003) TOT(2003) = 1012  TOT/2 = 506 The median cited age is 6.53 The number of articles published during these 6.53 years is The 2003 MIF of Scientometrics is 506/ = < ISI IF (1.251). YPubl – cum.sum CitCum cit %

Recent trends Not just the ISI 2-year synchronous impact, but a whole battery of impact factors are used in science evaluation.

What should be the real purpose of research evaluation? The real goal of any form of research evaluation is providing those people and institutions that have the talent and motivations to carry out scientific research, with the best conditions possible under which to do so (Russell-Rousseau, 2002).

Evaluation and scientometric research Budgetary and other kinds of constraints make evaluations necessary for the equitable distribution of resources. The evaluation of short-term strategic research as well as long-term curiosity-driven search for new knowledge demands the same rigorous standards as scientific research itself. For this reason the application of bibliometric and scientometric techniques in research evaluation must keep up with the rapid changes occurring in scientific communication patterns. Information scientists must also constantly improve the theoretical foundation for the construction of output and impact indicators supporting peer review (Russell-Rousseau, 2002)