Impact factor (IF) is on of the most important indicators of academic influence of a publication. The coefficient is published in the database Journal Citation Reports, whose producer is the Institute for Scientific Information (ISI) in the United States. The value is measured in the context of serial publications (journals) and is calculated and published annually.
The so-called h-index that measures the publication activity of individual authors or groups of authors is calculated from the number of citations from their works published in journals. On the basis of the database Web of Science, the h-index may be calculated for every single academic worker as well as entire institutions. At the present date, the h-index of Palacký University is 104.
Among Czech scientists today, the author with perhaps the highest h-index is the director of several prestigious research laboratories in Europe and one of the teams at the Institute of Molecular and Translational Medicine in Olomouc, Jiří Bártek - h-index 104. According to recent calculations of the h-index of UP scientists, he is followed by Pavel Hobza (h-index 91), Miroslav Strnad (46), Jaroslav Doležel (45), Vladimír Janout (40), Radek Zbořil (36), Jitka Ulrichová (34), Marián Hajdúch (31), Michal Otyepka (30) and Bohuslav Melichar (30).
(According to WoS as of June 8, 2015.)
The calculation of Impact factor is based on citations over three years. It is defined as the ratio of the number of citations that were recorded in the assessed year to all articles published in the given journal during the previous two years. Values above 40 are considered high impact factor values – e.g. the journal Nature had an impact factor of 42 351 in the year 2014, while the journal Science had an impact factor of 31 453. Impact factors for individual years and journals that are included in the Web of Knowledge database can be found at www.isiknowledge.com/JCR.
The H-index (or Hirsch index) indicates the number of articles (h) with higher or equal number of citations as the number of those articles (h), and expresses the scientific output of a researcher. Similarly to the impact factor the Hirsch index does not compare the performance of authors in all fields and is linked to a scientific discipline. Apparently the highest Hirsch index in physics belonged to Edward Witten, co-founder of superstring theory, whose h-index in 2005 was 110.