In most scientometric studies, the indicators are derived and inferred from the calculation and counting of four variables: authorship, publication, citation, and citation. The citation index is one of the most common and reliable scientometric indicators due to its relative attention to quality and its high efficiency in citation analysis. The most important scientometric indicators that have been formed based on the citation index and citation analysis and have been repeatedly referred to in various texts include: impact factor, urgency index, half-life of scientific texts or text obsolescence, Hirsch index, Matthew impact, and methods of measuring science that are used in different countries and institutions.
Impact Factor: The impact factor was first proposed in 1995 by the founder of ISI and quickly became a guideline for selecting the best journals. In the ISI journal ranking, the impact factor is the most widely used index today in the ranking and evaluation of journals. This index is widely used today in the ranking and evaluation of journals, in fact, it shows the ability of the journal and its editorial board to attract the best articles. The impact factor is defined as the average citations to a citation item (such as a research article, review, letter to the editor, note, abstract, etc.) in a scientific journal over a given period of time. In other words, the number of citations to documents published in the previous two years of the journal divided by the number of documents published in the same two years. The impact factor is a measure used to evaluate a journal and is one of the most important indicators in the field of scientometrics. At the end of each year, journals covered by ISI are evaluated. To access the impact factor of journals, the JCR database can be used.
Citation & Self Citation: Citation means the number of times an article is used and documented. Self-citation means referring to the author's own articles. Of course, self-citation is not insignificant, but in examining the references made to an article, the references of others are more important than the researcher's own references. The degree of self-citation in ISI journals is usually less than 20%.
H-Index: H-Index is a scientometric index that, in addition to measuring the scientific production of individuals, also determines their scientific impact and quantitatively displays the productivity and impact of researchers. This index is calculated by considering the number of highly cited articles of individuals and the number of times those articles are cited by others. H-Index can also be used to calculate the scientific impact of universities and researchers in a country. The definition of the H-index for a researcher is the number of h articles of which each article has been cited at least h times. The H-index is calculated based on the citations given to the published works of an individual or group of individuals. For example, when we say that an individual's H-index is 5, it means that this person has 5 articles, each of which has been cited at least 5 times.
G-Index: A researcher's g-index is the highest number (g) of papers cited by g to the power of 2 or more.
Immediacy Index: This index is determined at the end of each year and is used to determine the citation rate of a journal's articles. This index is the ratio of the number of citations to articles published in a journal to the number of articles published in that journal in the same year.
Cited half Life: The citation half-life of a journal is the time it takes for half of all citations to be made to that journal. A higher half-life for a journal can indicate the enduring value of that journal's articles.
M-Index: The Hirish index of each researcher depends on the duration of his research activity. Because over time, the number of articles and citations to it increases. Therefore, to compare researchers at different stages of their activity, the M index was introduced. This parameter is obtained by dividing the Hirish index of each researcher by his scientific age. Scientific age is the number of years that have passed since the publication of his first article.
Y-Index: The Y-index is used to assess the contribution of publications by authors, institutions, and countries. It is related to the number of Corresponding Author Publications, RP, and First Author Publications, FP. The Y-index consists of two parameters: the publication function, j, which is related to the quantity of publications, and the publication character, h, which is the ratio of corresponding author publications to first author publications. The parameters j and h are defined as follows:
Mathew Value: It is one of the new scientometric indicators introduced by Moyage in 2006. In fact, this indicator is a modified form of the impact factor that calculates it over a five-year period and in a specific subject. The way it is calculated is to divide the number of citations to articles in a journal over a five-year period by the number of articles in the same journal over the same period, and then scale the resulting number with the same ratios across the entire field of study. If the number of citations to all articles in a journal over a five-year period is W; the total number of articles in this journal over the same five-year period is X; the number of citations to articles in that journal in a specific subject area is Y; and the total number of articles in this area is Z, the Matthew value will be as follows: For example, if the number of citations to all articles in a journal in the years 2005 to 2010 is 53,400; the total number of articles in this journal over the same five-year period is 1,680; If the number of citations to articles in that journal in the field of biophysics is 18,500; and the total number of articles in this field is 470, the Matthew value is 0.8.
Impact Factor: The impact factor was first proposed in 1995 by the founder of ISI and quickly became a guideline for selecting the best journals. In the ISI journal ranking, the impact factor is the most widely used index today in the ranking and evaluation of journals. This index is widely used today in the ranking and evaluation of journals, in fact, it shows the ability of the journal and its editorial board to attract the best articles. The impact factor is defined as the average citations to a citation item (such as a research article, review, letter to the editor, note, abstract, etc.) in a scientific journal over a given period of time. In other words, the number of citations to documents published in the previous two years of the journal divided by the number of documents published in the same two years. The impact factor is a measure used to evaluate a journal and is one of the most important indicators in the field of scientometrics. At the end of each year, journals covered by ISI are evaluated. To access the impact factor of journals, the JCR database can be used. Citation & Self Citation: Citation means the number of times an article is used and documented. Self-citation means referring to the author's own articles. Of course, self-citation is not insignificant, but in examining the references made to an article, the references of others are more important than the researcher's own references. The degree of self-citation in ISI journals is usually less than 20%.Types of self-citation: Author self-citation: If the author has cited one or more of his previous articles in an article, this method is defined as self-citation.
Journal self-citation: Referring to articles published in the journal in which the citing article was published is called journal self-citation.
Organizational self-citation: Citations of articles authored by individuals to the organization in which they work are also called organizational self-citation.
H-Index: H-Index is a scientometric index that, in addition to measuring the scientific production of individuals, also determines their scientific impact and quantitatively displays the productivity and impact of researchers. This index is calculated by considering the number of highly cited articles of individuals and the number of times those articles are cited by others. H-Index can also be used to calculate the scientific impact of universities and researchers in a country. The definition of the H-index for a researcher is the number of h articles of which each article has been cited at least h times. The H-index is calculated based on the citations given to the published works of an individual or group of individuals. For example, when we say that an individual's H-index is 5, it means that this person has 5 articles, each of which has been cited at least 5 times.Web-based citation databases for calculating the H-index are:
Web of Science
Scopus
Google Scholar
G-Index: A researcher's g-index is the highest number (g) of papers cited by g to the power of 2 or more. Immediacy Index: This index is determined at the end of each year and is used to determine the citation rate of a journal's articles. This index is the ratio of the number of citations to articles published in a journal to the number of articles published in that journal in the same year. Cited half Life: The citation half-life of a journal is the time it takes for half of all citations to be made to that journal. A higher half-life for a journal can indicate the enduring value of that journal's articles. M-Index: The Hirish index of each researcher depends on the duration of his research activity. Because over time, the number of articles and citations to it increases. Therefore, to compare researchers at different stages of their activity, the M index was introduced. This parameter is obtained by dividing the Hirish index of each researcher by his scientific age. Scientific age is the number of years that have passed since the publication of his first article. Y-Index: The Y-index is used to assess the contribution of publications by authors, institutions, and countries. It is related to the number of Corresponding Author Publications, RP, and First Author Publications, FP. The Y-index consists of two parameters: the publication function, j, which is related to the quantity of publications, and the publication character, h, which is the ratio of corresponding author publications to first author publications. The parameters j and h are defined as follows:Different values indicate different ratios of RP to FP. When the number of first author publications and corresponding author publications are the same, the Y-index lies on a line with an angle of 45 degrees. Therefore, is equal to 45 degrees or 0.7854 radians. Smaller than 0.7854 and larger than 0.7854 correspond to larger FP and RP values, respectively. When j is equal to the number of first author publications, and when j is equal to the number of corresponding author publications.
Mathew Value: It is one of the new scientometric indicators introduced by Moyage in 2006. In fact, this indicator is a modified form of the impact factor that calculates it over a five-year period and in a specific subject. The way it is calculated is to divide the number of citations to articles in a journal over a five-year period by the number of articles in the same journal over the same period, and then scale the resulting number with the same ratios across the entire field of study. If the number of citations to all articles in a journal over a five-year period is W; the total number of articles in this journal over the same five-year period is X; the number of citations to articles in that journal in a specific subject area is Y; and the total number of articles in this area is Z, the Matthew value will be as follows: For example, if the number of citations to all articles in a journal in the years 2005 to 2010 is 53,400; the total number of articles in this journal over the same five-year period is 1,680; If the number of citations to articles in that journal in the field of biophysics is 18,500; and the total number of articles in this field is 470, the Matthew value is 0.8.