چکیده:
Since reference practices influence Journal Impact Factor (JIF), Author Self-
Citation (ASC), number of times an author cites herself / himself, and
Journal Self-Citation (JSC), number of times the journal cites itself, as a
portion of total citations should be considered in citation analysis. ISI
provides quantitative indicators for publications in English language.
Therefore, those scientific journals in different countries that publish in
national languages have less chance to be evaluated based on bibliometric
indicators. For this reason, Regional Information Center for Science and
Technology (RICeST) affiliated to the Ministry of Science, Research and
Technology of Iran started to construct the Persian Science Citation Index
(PSCI) and Persian Journal Citation Reports (PJCR) as products of ISC in
2000, and released the services from 2004. PJCR and PSCI are used to
conduct the research. At the time of the study 51 Persian engineering
journals were indexed in ISC with IF in PJCR. The aim of the study is to
find if the JIF is affected by both ASC and JSC for Persian journals in
engineering subject category during 2002-2006. The results show that within
the five years mean rates for JSC and ASC are 41% and 66%, respectively.
Findings also report that the correlation between JSC and ASC with IF is
statistically significant (R= 0.300, sig. = 0.032; R= 0.397, sig. = 0.004,
respectively). Moreover, after self-citation removal, the maximum rankings
change was observed (either positive or negative). With or without inclusion
of author self-citations and journal self-citations about 13.7% and 15.7% of
journals maintained the position. There is also no correlation between JIF
and the number of articles (R= - 0.031, sig. = 0.831). According to the
findings, the study suggests that Persian journals' editorial boards in
engineering field implement a policy with regard to articles selection as well
as authors' citation behavior.
خلاصه ماشینی:
According to the findings, the study suggests that Persian journals' editorial boards in engineering field implement a policy with regard to articles selection as well as authors' citation behavior.
The study showed a significant influence of self-citations on six journals Impact Factor in aneasthesia.
Recalculation of Impact Factor for library and information science and genetics journals after removing self-citation was done by Nisonger (2000).
M'cveigh (2004) showed there is a weak correlation between self citation rate and the size of a journal and also with the impact factor and subject of a journal.
Yu and Wang (2007) investigated journal self-citation rate and its impact factor in three levels (i.
The results showed that journals with medium impact factors are more affected by self-cited rate.
Ghane (2008) studied both author and journal self-citations in medical sciences using ISC's PJCR (2005 version).
Findings showed there is a positive correlation between journal self-citation and impact factor.
The formulae used calculating self-cited rates for each of five years is as below: (2) Number of times the journal cited by itself in a given year (here 2002-2006) * 100 Number of total cites received by the journal from all journals in a given year (here 2002-2006) (3) Number of times an author cited herself / himself in a given year (here 2002-2006) * 100 Number of total cites received by the journal from all journals in a given year (here 2002-2006) Since the study aims to investigate the influence of self-citation on journal impact factor, number of citations, self-citations, and JIFs extracted from PJCR for years 2002- 2006 are ranked according to their IF for each of the five years.