I do not understand about the 5 year impact factor, yearly IF, how IF can increase, and what the IF really means?
It depends on the number of citations that articles in the journal have received within a specific time
Impact Factor calculation is an attempt to create a quantitative tool for evaluating journals. It represents the frequency with which the "average article" in a journal has been cited in a given period of time. For example: if there are 100 papers published in a journal in 2009-2010 and there are 100 citations of articles from this journal in 2011 the Impact Factor'2011 is 1 (number of published articles/number of citations). As you can presume the IF of a journal is changed each year. The IF is calculated by Thomson Reuters and you can find detailed information at:
http://thomsonreuters.com/products_services/science/free/essays/impact_factor/
The impact factor of a journal reflects the frequency with which the journal's articles are cited in the scientific literature. It is derived by dividing the number of citations in year 3 to any items published in the journal in years 1 and 2 by the number of substantive articles published in that journal in years 1 and 2 [1]. For instance, the year 2002 impact factor for Journal X is calculated by dividing the total number of citations during the year 2002 to items appearing in Journal X during 2000 and 2001 by the number of articles published in Journal X in 2000 and 2001 (Figure 1). Conceptually developed in the 1960s, impact factor has gained acceptance as a quantitative measure of journal quality [2]. Impact factor is used by librarians in selecting journals for library collections, and, in some countries, it is used to evaluate individual scientists and institutions for the purposes of academic promotion and funding allocation [3, 4]. Not surprisingly, many have criticized the methods used to calculate impact factor [5, 6]. However, empiric evaluations of whether or not impact factor accurately measures journal quality have been scarce [7].
Impact factor: a valid measure of journal quality?
Authors: Somnath Saha, Sanjay Saint, and Dimitri A. Christakis,
retrieved from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC141186/
Is the Impact Factor (IF) an ideal and accurate measure of a journals's credibility and quality? Aren't there any loop holes/criticism in this type of measuremen?
Impact factor of a journal is an index based on the frequency with which a journal's articles are cited in scientific publications. In any given year, the impact factor of a journal is the average number of citations received per paper published in that journal during the two preceding years. It is derived by dividing the number of citations in year 3 to all articles published in the journal during preceding years 1 and 2 by the number of citable articles published in that journal in years 1 and 2.
The impact factor is a measure of the frequency with which the "average article" in a journal has been cited in a particular year or period. The annual JCR impact factor is a ratio between citations and recent citable items published. Thus, the impact factor of a journal is calculated by dividing the number of current year citations to the source items published in that journal during the previous two years.
The 2013 impact factor of a journal would be calculated as follows:
2013 impact factor = A/B.
where:
A = the number of times that all items published in that journal in 2011 and 2012 were cited by indexed publications during 2013.
B = the total number of "citable items" published by that journal in 2011 and 2012. ("Citable items" for this calculation are usually articles, reviews, proceedings, or notes; not editorials or letters to the editor).
http://www.citefactor.org/journal-impact-factor-list-2014.html
@ Mr. Alexander Julianov: The corect fraction for IF is: number of citations/ number of published articles, for the period analysed (last 3 years in ISI).
IF measure the quality and potential of journal. It is nothing but the frequency with which average articles has been cited in a given period of time. IF is a important tool that noteworthy determine the qualitative and quantitative analysis of jopurnals.
Simply, IF means: Total number of citation/Total number of articles published in a time period. For example: if there are 100 papers published in a journal in 2014 and there are 50 citations of articles from this journal in 2014, the Impact factor'2015 is 0.5 . It expressed it's quality and acceptability. Thank you.
The journal Impact Factor is the average number of times articles from the journal published in the past two years have been cited in the JCR year. The Impact Factor is calculated by dividing the number of citations in the JCR year by the total number of articles published in the two previous years. An Impact Factor of 1.0 means that, on average, the articles published one or two year ago have been cited one time. An Impact Factor of 2.5 means that, on average, the articles published one or two year ago have been cited two and a half times. The citing works may be articles published in the same journal. However, most citing works are from different journals, proceedings, or books indexed by Web of Science.
The impact factor (IF) of an academic journal is a measure reflecting the average number of citations to recent articles published in that journal. It is frequently used as a proxy for the relative importance of a journal within its field, with journals with higher impact factors deemed to be more important than those with lower ones. The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information. Impact factors are calculated yearly starting from 1975 for those journals that are indexed in the Journal Citation Reports
@ Sharma Rao Balakrishnan
You can see on Elsevier
Measuring a journal’s impact
Scopus journal metrics
Understanding the impact of a journal can help you decide whether to submit your article.
Impact per Publication (IPP) is comparable to the Impact Factor, but uses a citation window of three years, which is considered to be the optimal time period to accurately measure citations in most subject fields. Taking into account the same peer-reviewed scholarly papers in both the numerator and denominator of the equation provides a fair impact measurement of the journal and diminishes the chance of manipulation. IPP measures the ratio of citations in a year (Y) to scholarly papers published in the three previous years (Y-1, Y-2, Y-3) divided by the number of scholarly papers published in those same years (Y-1, Y-2, Y-3).
Source Normalized Impact per Paper (SNIP) provides a novel bibliometric perspective, correcting for subject-specific characteristics of the field someone is publishing in. This means that, unlike the Impact Factor, SNIP numbers can be compared for any two journals, regardless of the field they are in. SNIP is defined as the ratio of the raw Impact per Publication divided by the Relative Database Citation Potential. The raw Impact per Publication is the same as IPP. The resulting ratio is then divided by the Relative Database Citation Potential.
SCImago Journal Rank (SJR) is based on citation data of the more than 20,000 peer-reviewed journals indexed by Scopus from 1996 onwards. Citations are weighted, depending on the rank of the citing journal: A citation from an important journal will count as more than one citation; a citation coming from a less important journal will count as less than one citation. The SJR of journal J in year X is the number of weighted citations received by J in X to any item published in J in (X-1), (X-2) or (X-3), divided by the total number of articles and reviews published in (X-1), (X-2) or (X-3).
The h-index is a metric for evaluating individual scientists – it rates a scientist's performance based on their career publications, as measured by the lifetime number of citations each article receives. The measurement is dependent on both quantity (number of publications) and quality (number of citations) of an academic's publications. If you list all of a scientist's publications in descending order of the number of citations received to date, their h-index is the highest number of their articles, h, that have each received at least h citations. So, their h-index is 10 if 10 articles have each received at least 10 citations; their h-index is 81 if 81 articles have each received at least 81 citations.
The journal Impact Factor is published every year by Thomson Reuters. It measures the number of times an average paper in a particular journal has been referred to.
The Impact Factor of journal J in the calendar year X is the number of citations received by J in X to any item published in J in (X-1) or (X-2), divided by the number of source items published in J in (X-1) or (X-2). The Impact Factor can be a useful way of comparing citability of journals, but the absolute Impact Factor is of limited use without those of other journals in the field against which to judge it. You can find the most recent Impact Factors of our individual journals on their homepages.
The Five-year Impact Factor is similar in nature to the regular 'two-year' Impact Factor, but instead of counting citations in a given year to the previous two years and dividing by source items in these years, citations are counted in a given year to the previous five years and again divided by the source items published in the previous five years. While still showing changes over time, the five-year measure presents a much smoother variation.
Other journal metrics
Immediacy Index: Published by Thomson Reuters, the Immediacy Index is a measure of the speed at which content in a particular journal is picked up and referred to. The Immediacy Index of journal J in the calendar year X is the number of citations received by J in X to any item published in J in X, divided by the number ofsource items published in J in X.
Cited Half-Life: Published by Thomson Reuters, the Cited Half-Life is a measure of the 'archivability' of content in a particular journal, or of how long content is referred to after publication. The Cited Half-Life of journal J in year X is the number of years after which 50% of the lifetime citations of J's content published in X have been received.
The Eigenfactor and Article Influence are based on data held in Thomson Reuters' Journal Citation Reports. The Eigenfactor of journal J in year X is defined as the percentage of weighted citations received by J in X to any item published in (X-1), (X-2), (X-3), (X-4), or (X-5), out of the total citations received by all journals in the dataset. Only citations received from a journal other than J are counted. Article Influence is calculated by dividing the Eigenfactor by the percentage of all articles recorded in the Journal Citation Reports that were published in J. Article Influence is therefore conceptually similar to the Impact Factor and SCImago Journal Rank.
As per web of science and scopus, generally 2 year Impacts are considered to calculate impact factor.
Impact factor for year X is the average citations per paper published in previous two years, in the year X.
For example, in a particular journal, there are 100 papers published in 2011 and 150 papers published in 2012. In the year 2013 only, these 250 articles were cited 750 times. Then,
Impact factor (2013)= total no. of citations obtained in 2013 from previous two year publications/ total no. of papers published in 2011 and 2012
= 750/250= 3.
Similarly, 5 year impact factor is calculated. The citations will be more and the number of articles will also be more. In the above example, we would have considered the number of publications in 2012,2011,2010,2009 and 2008 for denominator and all citations obtained by these articles in 2013 as numerator.
Simple!
The impact factor reflects the yearly average number of citations to recent articles published in the journal.
it is very easy to calculate impact factor of a journal.
(A) step 1 is. add published articles of previous year
(B) step 2 is. check citation of this journal
step 3 is. B/A=impact factor
Dear Readers
http://iarcif.org/index.php/evaluation_methodology
IARC-IF is a measure reflecting the average number of citations to articles published in journals, books, patent document, thesis, project reports, newspapers, conference/ seminar proceedings, documents published in internet, notes and any other approved document. It is a measure of the frequency with which the average article in a journal has been cited in a given period of time. The annual JCRR impact factor is a ratio between citations, reference and recent citable items published. The impact factor for a journal is calculated on the basis of a three-year period and can be considered to be the average number of times published papers are cited and its articles have been referenced in other articles up-to two years after publication. Also IARC calculated based on governance and commercial quality, scientific quality, editorial quality, international presence and Infrastructure, Stability, Standards, Contextual citation. In general high impact factor journals are recognized as the most influential as compared to the other journals published in the same field. The IF is used to compare different journals within a certain field. The 'International Accreditation and Research Council' indexes many Arts, Agriculture, Science, Computer Science, Engineering, Information Technology, Commerce, Management, Economics Sociology and Social Science journals. Those journals are indexed in Journal Citation Reference Reports (JCRR).
Evaluation Methodology
A) Calculation of yearly impact factor based on three year period.
1. X=Total cites in 2009
2. Y= 2009 cites to articles published in 2007-08 (This is subset of X)
3. Z= Number of articles published in 2007-08
4. IF=Y/Z=2009 impact factor
Actual Calculation of impact factor in 2009
Cites in 2009 to articles published in:
2008 = 456
2007 = 468
Total = 924
Number of articles published in:
2008 = 80
2007 = 74
Total = 154
Impact factor = cites to recent articles/number of recent articles = 924/154=6.0
B) Calculation of five year impact factor
1. X= Citations in 2011 over the 2006-2010
2. Y= Articles published over the years 2006-2010
3. Z= X/Y = Five year impact factor (Source: Web of Knowledge)
The impact factor is useful in clarifying the significance of absolute citation frequencies. It eliminates some of the bias of such counts which favor large journals over small ones, or frequently issued journals over less frequently issued ones, and of older journals over newer ones. Particularly in the latter case such journals have a larger citable body of literature than smaller or younger journals. All things being equal, the larger the number of previously published articles, the more often a journal will be cited.
There have been many innovative applications of journal impact factors.
1. It is important for market research for publishers and others.
2. This is an important tool for librarians, researchers and for the librarians.
3. It is also an important tool for researcher to select a reputed journal and publish in elderly and reputed journals.
4. The impact factor can be used to provide a gross approximation about the prestige of a journal. 5. It is also a tool for sensible use and quote of data with proper care in the journals.
In general authors should keep in mind that
1. Impact factor can be calculated after completing the minimum of 3 years of publication.
2. Journal Impact Factor will be a quotient factor only and will not be a quality factor.
3. Journal Impact Factor will not be related to quality of content and quality of peer review.
4. Journal which publishes more review articles will get highest impact factors.
5. The impact factor is highly discipline dependent.
6. The impact factor could not be reproduced in an independent audit.
7. The impact factor refers to the average number of citations per paper.
8. Counting citations may be independent of the real 'impact' of the work among investigators and scientific communities.
9. Self-citations and purposeful addition of the same journal article with the favorable editorial policies may cause the journals or publishers to be not considered for the evaluation of the impact factor.
10. The IF may be incorrectly applied to evaluate the significance of an individual publication or to evaluate an individual researcher.
11. A title change affects the impact factor for two years after a change is made. The old and new titles are not unified unless the titles are in the same position alphabetically.
Advantages of Impact Factor (IARC)
There are many advantages of journal citation impact factors. The most common one involves market research for publishers and others. But, primarily, IARC provides librarians, scientists and researchers with a tool for the management of library journal collections. In market research, the impact factor provides quantitative evidence for editors and publishers for positioning their journals in relation to the competition especially others in the same subject category, in a vertical rather than a horizontal or interdisciplinary comparison. As a tool for management of library journal collections, the impact factor supplies the library administrator with information about journals already in the collection and journals under consideration for acquisition. These data must also be combined with cost and circulation data to make rational decisions about purchases of journals. Perhaps the most important and recent use of impact factor is in the process of academic evaluation. The impact factor can be used to provide a gross approximation of the prestige of journals in which individuals have been published. This is best done in consideration with other considerations such as peer review, productivity, and subject specialty citation rates. The impact factor can be useful in all of these applications, provided the data are used sensibly. It is important to note that qualitative methods can be used in evaluating journals such as interviews, questionnaires, schedules etc. In general, there is good agreement on the relative value of journals in the appropriate categories. However, the IARC makes possible the realization that many journals do not fit easily into established categories.
IARC does not recommend the 'IARC Impact Factor' as the only important metrics for assessing the usefulness of a journal. Rather IARC does not depend on the impact factor alone in assessing the usefulness of a journal. The impact factor should not be used without careful attention to the many phenomena that influence citation rates, as the average number of references cited in the average article. In the case of academic evaluation for tenure it is sometimes inappropriate to use the impact of the source journal to estimate the expected frequency of a recently published article. Again, the impact factor should be used with informed peer review. Citation frequencies for individual articles are quite varied.
http://iarcif.org/index.php/evaluation_methodology
IF = Total number of citations in the time period / average number of publications in the time period.
To calculate the Five-years Impact Factor IF ( Assume the current year 2016)= The citation are counted in 2016 to the previous five years divided by the source items published in the previous five years.
i.e. IF=Total citations are counted 2016-2012 / Total paper published in 2016-2012
which is calculated by JCR (Clarivate Analytics)
2017 impact factor= (citation 2016+citation 2015)/(Publications2016+Publications2015)
But JIF is by JCR (Clarivate Analytics and all of us know the way.
Some researchers think that everebody can calculate JIF.
There are always correction by JCR. Below is interesting explanation
http://stateofinnovation.com/a-closer-look-at-the-journal-impact-factor-numerator
IF for the year 2016
=Total no. of citations for particular year2015 /total no of papers published in that particular year
Example=15/48=.312
http://iarcif.org/index.php/evaluation_methodology
Evaluation Methodology
IARC was established by a group of renowned researchers, scientists, engineers and academicians having multi geographical representations with an objective of providing quality metrics and journal analytics to the researcher. Impact factors are calculated yearly for those journals that are indexed in 'International Accreditation and Research Council' 'Journal Citation Reference Reports' (JCRR). JCRR provides quantitative tools for evaluating, categorizing and comparing journals. The IF is a measure of average number of citations and reference to the articles published in arts, agriculture and forestry sciences, animal, veterinary and fishery sciences, biological sciences, chemical sciences, computer and information technology sciences, earth sciences, engineering sciences (civil, cybernetics electrical, electronics, mechanical, textile), environmental sciences, forensic sciences, family, community and consumer sciences, home sciences, humanity sciences, library sciences, material sciences mathematical and statistical sciences, medical sciences, military sciences, pharmaceutical sciences, physical sciences, physical education sciences, educational sciences: for school students, women, village and society, commerce, law and management related with sciences, anthropological and behavioral sciences: sociology, social sciences: researches in the field of economics, political science, geography, drawing, music, dance, philosophy, history and languages concerning with science, journalism and role of media in science, role of NGOs in the protection of environment journals.
IARC-IF is a measure reflecting the average number of citations to articles published in journals, books, patent document, thesis, project reports, newspapers, conference/ seminar proceedings, documents published in internet, notes and any other approved document. It is a measure of the frequency with which the average article in a journal has been cited in a given period of time. The annual JCRR impact factor is a ratio between citations, reference and recent citable items published. The impact factor for a journal is calculated on the basis of a three-year period and can be considered to be the average number of times published papers are cited and its articles have been referenced in other articles up-to two years after publication. Also IARC calculated based on governance and commercial quality, scientific quality, editorial quality, international presence and Infrastructure, Stability, Standards, Contextual citation. In general high impact factor journals are recognized as the most influential as compared to the other journals published in the same field. The IF is used to compare different journals within a certain field. The 'International Accreditation and Research Council' indexes many Arts, Agriculture, Science, Computer Science, Engineering, Information Technology, Commerce, Management, Economics Sociology and Social Science journals. Those journals are indexed in Journal Citation Reference Reports (JCRR).
Evaluation Methodology
A) Calculation of yearly impact factor based on three year period.
1. X=Total cites in 2009
2. Y= 2009 cites to articles published in 2007-08 (This is subset of X)
3. Z= Number of articles published in 2007-08
4. IF=Y/Z=2009 impact factor
Actual Calculation of impact factor in 2009
Cites in 2009 to articles published in:
2008 = 456
2007 = 468
Total = 924
Number of articles published in:
2008 = 80
2007 = 74
Total = 154
Impact factor = cites to recent articles/number of recent articles = 924/154=6.0
B) Calculation of five year impact factor
1. X= Citations in 2011 over the 2006-2010
2. Y= Articles published over the years 2006-2010
3. Z= X/Y = Five year impact factor (Source: Web of Knowledge)
The impact factor is useful in clarifying the significance of absolute citation frequencies. It eliminates some of the bias of such counts which favor large journals over small ones, or frequently issued journals over less frequently issued ones, and of older journals over newer ones. Particularly in the latter case such journals have a larger citable body of literature than smaller or younger journals. All things being equal, the larger the number of previously published articles, the more often a journal will be cited.
There have been many innovative applications of journal impact factors.
1. It is important for market research for publishers and others.
2. This is an important tool for librarians, researchers and for the librarians.
3. It is also an important tool for researcher to select a reputed journal and publish in elderly and reputed journals.
4. The impact factor can be used to provide a gross approximation about the prestige of a journal. 5. It is also a tool for sensible use and quote of data with proper care in the journals.
In general authors should keep in mind that
1. Impact factor can be calculated after completing the minimum of 3 years of publication.
2. Journal Impact Factor will be a quotient factor only and will not be a quality factor.
3. Journal Impact Factor will not be related to quality of content and quality of peer review.
4. Journal which publishes more review articles will get highest impact factors.
5. The impact factor is highly discipline dependent.
6. The impact factor could not be reproduced in an independent audit.
7. The impact factor refers to the average number of citations per paper.
8. Counting citations may be independent of the real 'impact' of the work among investigators and scientific communities.
9. Self-citations and purposeful addition of the same journal article with the favorable editorial policies may cause the journals or publishers to be not considered for the evaluation of the impact factor.
10. The IF may be incorrectly applied to evaluate the significance of an individual publication or to evaluate an individual researcher.
11. A title change affects the impact factor for two years after a change is made. The old and new titles are not unified unless the titles are in the same position alphabetically.
Advantages of Impact Factor (IARC)
There are many advantages of journal citation impact factors. The most common one involves market research for publishers and others. But, primarily, IARC provides librarians, scientists and researchers with a tool for the management of library journal collections. In market research, the impact factor provides quantitative evidence for editors and publishers for positioning their journals in relation to the competition especially others in the same subject category, in a vertical rather than a horizontal or interdisciplinary comparison. As a tool for management of library journal collections, the impact factor supplies the library administrator with information about journals already in the collection and journals under consideration for acquisition. These data must also be combined with cost and circulation data to make rational decisions about purchases of journals. Perhaps the most important and recent use of impact factor is in the process of academic evaluation. The impact factor can be used to provide a gross approximation of the prestige of journals in which individuals have been published. This is best done in consideration with other considerations such as peer review, productivity, and subject specialty citation rates. The impact factor can be useful in all of these applications, provided the data are used sensibly. It is important to note that qualitative methods can be used in evaluating journals such as interviews, questionnaires, schedules etc. In general, there is good agreement on the relative value of journals in the appropriate categories. However, the IARC makes possible the realization that many journals do not fit easily into established categories.
IARC does not recommend the 'IARC Impact Factor' as the only important metrics for assessing the usefulness of a journal. Rather IARC does not depend on the impact factor alone in assessing the usefulness of a journal. The impact factor should not be used without careful attention to the many phenomena that influence citation rates, as the average number of references cited in the average article. In the case of academic evaluation for tenure it is sometimes inappropriate to use the impact of the source journal to estimate the expected frequency of a recently published article. Again, the impact factor should be used with informed peer review. Citation frequencies for individual articles are quite varied.
The SCI Journals have a high impact factors because they published free cost your research artists
The SCI Journals have a high impact factors because they published free cost your research article
1s ago
Five years IF=Total citations received in 2017 over years 2016-2012/Total articles published in 2016-2012
Example,
Citation Received in 2016=800 of published articles 400
Citation Received in 2015=750 of published articles 350
Citation Received in 2014= 800 of published articles 250
Citation Received in 2013=750 of published articles 300
Citation Received in 2012= 800 of published articles 300,
Consequently, Five years IF in 2017=3900/1600
=2.437
Although IF may be a useful measure of the utility of a particular journal, it is just a number and is based on requirement that a journal be "indexed" by some self-important and self-appointed service. A new journal must have an IF of zero in its initial period of publication and that will remain zero until enough time has passed for articles to start to become cited. Some good journals do not have "Indexing service" impact factors because those services can refuse to include journals for indexing. Thus, IF can be useful but is not fair as presently practiced because all scholarly journals are not "indexed". The major publishing houses promote their own journals and probably subscribe to "indexing services" (i.e. buy their way in) to gain a scholastically unfair advantage over lesser light journals (even though this practice may be regarded as being good business sense in regard to promoting sales of journals) that are unable (for various reasons) to become "indexed".
In recent years, there has become not just a plethorization of journals but also a growth in the "indexing-service" sector. The intellectual honesty, integrity, and objectivity of IF has become rather suspect and IF statistics now need to be treated with skepticism and care as being biased by lack of completeness of coverage (indexing), costs (payment for indexing service) and perhaps other issues that I have not considered.
Peter Kevan
The impact factor (IF) or journal impact factor (JIF) of an academic journal is a measure reflecting the yearly average number of citations to recent articles published in that journal. It is frequently used as a proxy for the relative importance of a journal within its field; journals with higher impact factors are often deemed to be more important than those with lower ones. The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information. Impact factors are calculated yearly starting from 1975 for journals listed in the Journal Citation Reports.
source "wikipedia"
The impact factor is based on two figures: the number of citations to a given journal over the previous two years (A) and the number of research articles and review articles published by that journal over the same two-year period (B), so: Impact Factor = A/B
In fact I wonder why are we interested in IF calculation? If a journal has a good impact factor, try to publish in it.
Dear, Thomson Reuters impact factor is universally accepted impact factor. However, there are several impact factor calculation like Google based, universal, scientific etc.
A Thomson Reuters impact factor is based on JCR data. It is total no. citation received by an articles during the perticular year is divided by total no.of articles published during the preceding two years.
Dear you are lovely encourage for publish data in only Scopus and SCI journals.
The impact factor (IF) or journal impact factor (JIF) of an academic journal is a measure reflecting the yearly average number of citations to recent articles published in that journal. It is frequently used as a proxy for the relative importance of a journal within its field; journals with higher impact factors are often deemed to be more important than those with lower ones. The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information. Impact factors are calculated yearly starting from 1975 for journals listed in the Journal Citation Reports.
I tried to check the impact factor of a particular journal by the formula discussed at this forum. But it did not work.
The 2017 impact factor of a journal would be calculated as follows:
2017 impact factor = A/B.
where:
A = the number of times that all items published in that journal in 2015 and 2016 were cited by indexed publications during 2017.
B = the total number of "citable items" published by that journal in 2015 and 2016.
For Example, Impact factor of Indian Journal of Animal Sciences should be = 1298 (Citations 2015 and 2016) / 541 (Total paper published 2015 and 2016) = 2.40; But its actual impact factor is 0.279.
So there would be some parameters also which would be considered for calculation of impact factor.
The calculation of impact factor is based on a two-year period and involves dividing the number of times articles were cited by the number of articles that were published in a journal.
Please look at the equation below:
IFy=(Cy-1+Cy-2)/ (Py-1+Py-2)
More details Latest Changes in Journal Impact Factor, please read this article: https://www.cusabio.com/c-20702.html
The impact factor (IF) of a journal is a simple average obtained by considering the number of citations that articles in the journal have received within a specific time frame. Journal IFs are calculated yearly and disclosed in the Journal Citation Reports (JCR) published by Thomson Reuters. The IF of a journal for a particular year is calculated on the basis of citations received for the papers published in that journal during the previous two years.
Read the following articles for more in-depth information on calculating the impact factor.
https://www.editage.com/insights/how-is-the-impact-factor-calculated-for-a-journal-whose-name-changes
https://researchguides.uic.edu/if/impact
Impact Factor (IF) = (No. of citations received in the previous two years/No. of articles published during the same period).Example: Let the sum of citations received for articles published in IEEE Trans. on Smart Grid in years 2016 and 2017 be 150 and the no. of articles published in the same trans. in 2016 and 2017 be 100.
Then the IF of IEEE Trans on Smart Grid for the year 2018 is 150/100 = 1.5.
As mentioned above, IF is normally calculated for two year period. A longer period, say five years, reflects the popularity of the journal better.Then it is given as 5-year IF.
It depends on the number of citations that articles in the journal have received within a specific time
As Rosie Liu mentioned above, the most useful formula for calculating of IF is IFy=(Cy-1+Cy-2)/ (Py-1+Py-2) where
y: A given year IF: The impact factor of a journal in a given year C: The number of citations articles received in a given year P: The number of articles published in a journal in a specific year
i-index=X in year T implies X=[total number of citations in year (T-1) and (T-2)]/[total number of published article in year (T-1) and (T-1)]
The Impact Factor of journal J in the calendar year X is the number of citations received by J in X to any item published in J in (X-1) or (X-2), divided by the number of source items published in J in (X-1) or (X-2).
Impact Factor(IF) The Impact Factor is based on two figures: One is the number of citations to a given journal over the previous two years (A).
Another one is the number of research articles and review articles published by that journal over the same two-year period (B).
Impact Factor = A/B
More-> https://www.ilovephd.com/how-journal-impact-factor-h-index-calculated/
The impact factor (IF) of an academic journal is a measure reflecting the yearly average number of citations to recent articles published in that journal. It is frequently used as a proxy for the relative importance of a journal within its field; journals with higher impact factors are often deemed to be more important than those with lower ones.
How is impact factor calculated?
In any given year, the impact factor of a journal is the number of citations, received in that year, of articles published in that journal during the two preceding years, divided by the total number of articles published in that journal during the two preceding years.
5 year impact factor=IF in five years(sum of citations in 5 years/articles published in five years)
yearly IF= IF in one year
how IF can increase=increase by increasing number of citations
what the IF really means? =citations/articles published
Many Colleagues have well explained the method of calculation of impact factor of a Journal in a particular year. However, they have forgotten to mention the importance of 'self citations' (citations that appear in the same journals) while calculating impact factor. I would like to explain it using an example.
The impact of a particular Journal for the year 2018 will be calculated as below:
A). Total citations that appear in 2018 of the articles published in a particular journal during the 2017 and 2016, say it is 480 and if out of these 180 citations are from the same journal (Self citations), so effective total citations considered for calculating impact factor will be as 480-180 = 300.
B) Total articles published in that particular journal during the last two years 2017 and 2016 (150 +150 = 300)
so
The impact factor of a particular journal for the year 2018 will be
A / B = 300/300 = 1.00
you can check your journals impact factor in this site: http://journalchecker.ir
IF= The number of Citation in certain period of time/publication in that period of time
IF = number of citations that articles in the journal have received within a specific time
IF=CITATIONS/ARTICLES PUBLISHED (in two years)
5 year impact factor=IF in five years(sum of citations in 5 years/articles published in five years)
yearly IF= IF in one year
Impakt factor ili faktor uticajnosti je mjera učestalosti kojom se citirani „prosječni rad“ u časopisu navodi u određenoj godini ili periodu.
Faktor uticaja časopisa izračunava se dijeljenjem broja citata iz tekuće godine sa izvornim stavkama objavljenim u tom časopisu u prethodne dvije godine.
Faktor uticaja časopisa za 2018. godinu izračunat će se na sledeći način:
Faktor uticaja 2018 = A / B.
Gdje je:
A = broj puta kada su sve stavke objavljene u tom časopisu u 2016. i 2017. citirane u indeksiranim publikacijama tokom 2018. godine.
B = ukupan broj "citiranih" objavljenih u tom časopisu u 2016. i 2017.
https://en.wikipedia.org/wiki/Impact_factor
2019 paper is not counted for impact factor of 2019. Only papers published in 2017 and 2018 are counted. The total citation of these papers till the counting time (don't know when) divided by the total number of papers is the impact factor of 2019. This should be the same for the impact factor calculation for a particular researcher.
Impact factor of a scientific journal is an index based on the frequency with which a journal's articles are cited in scientific publications. In any given year, the impact factor of a journal is the average number of citations received per paper published in that journal during the two preceding years.
The impact factor of a journal is calculated by dividing the number of current year citations to the source items published in that journal during the previous two years.
The 2019 impact factor of a journal would be calculated as follows:
2019 impact factor = A / B .
where:
A = the number of times that all items published in that journal in 2017 and 2018 were cited by indexed journal publications during 2019.
B = the total number of "citable items" published by that journal in 2017 and 2018. ("Citable items" for this calculation are usually articles, reviews, proceedings, or notes; not editorials or letters to the editor).
So, in calculation impact factor of a journal, article published during 2019 (the year for which impact factor calculated is not included)
Self Citation :
Most of the participant have well explained the method of calculation of impact factor of a Journal in a particular year. However, they have forgotten to mention the importance of 'self citations' (citations that appear in the same journals) while calculating impact factor. I would like to explain it using an example.
The impact of a particular Journal for the year 2018 will be calculated as below:
A). Total citations that appear in 2019 of the articles published in a particular journal during the 2018 and 2017, for example it is 480 and if out of these 180 citations are from the same journal (Self citations), so effective total citations considered for calculating impact factor will be as 480-180 = 300.
B) Total articles published in that particular journal during the last two years 2018 and 2017 (150 +150 = 300)
If during calculation of impact factor by simple formula apparently IF ( 2019) it seems to 480/300 = 1.6 , But that is not correct ( This is the point where Indexing agencies usually manipulate in favour of some journal due to various reason )
So the Correct (Real) impact factor of a particular journal for the year 2019 will be
A / B = 300/300 = 1.00
Most trusted and oldest and reliable agency to release impact factor of scientific journal is Thomson Reuters Journal Citation Reports, now it has been expended to include new scientific journal to calculate their impact factor is science citation index expanded.
Impact factor (IF) is used as a proxy for the relative importance of a journal within its field. IF is awarded to the journals indexed in Thomson Reuters Journal Citation Reports. IF has been criticised for manipulation and incorrect application.[1] In my Opinion self citation is one of the most important area where these agencies able to manipulate impact factor very easily in some favour by the journal . There are multiple factors that could bias the calculation of the IF [2]. These include coverage and language preference of the database, procedures used to collect citations, algorithm used to calculate the IF, citation distribution of journals, online availability of publications, negative citations, preference of journal publishers for articles of a certain type, publication lag, citing behaviour across subjects, and possibility of exertion of influence from journal editors.[3]
Interestingly, IF is not available for all indexed journals. In fact, not all journals indexed even in Index Medicus/MedLine/PubMed are indexed in the Thomson Reuters Journal Citation Reports. Similarly, not all journals indexed in Thomson Reuters Journal Citation Reports and consequently have an IF are listed in Index Medicus/PubMed/MedLine.
1. Fassoulaki A, Papilas K, Paraskeva A, Patris K. Impact factor bias and proposed adjustments for its determination. Acta Anaesthesiol Scand. 2002;46:902–5.
2. Not-so-deep impact. Nature. 2005;435:1003–4.
3. Malathi M, Thappa DM. The intricacies of impact factor and mid-term review of editorship. Indian J Dermatol Venereol Leprol. 2012;78:1–4.
IF of any journal is an index calculated by number of citations of articles of any journal in last five years divided by total number of articles published in that journal in last five years.
e.g no. of citations are 500 and total no. of articles published is 50 in last five years then IF of that journal is 10
number of citations in 2017-2018 = A
number of articles published in 2017-2018 = B
IF 2019 = A/B
The impact factor of a journal is calculated by dividing the number of current year citations to the source items published in that journal during the previous two years.
The researcher has asked basically these questions.
Here are their answers.
Q1. 5 year impact factor (IF): let us consider from 2014-2018. The IF is calculated in 2019.
Number of citations received by citable items (CN)
Number of published items in a given journal (PN)
IF in 2019 is the ratio between CN and PN
Note: Include the current year citation as well.
Q2. IF increases as follows
a) By doing more standard research
b) Research articles should be easily accessible by wider audience
c) Increased number of citations per article
Q3. Meaning of IF: The IF is just a scientometric index. It measures the scientific impact of a given journal.
In another meaning, journals with the high IF are considered generally to be more important than those with low IF.
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