title: Article and journal impact factor in various scientific fields.
abstract: BACKGROUND
  We tried to provide the scientific community with data to answer the following simple question: What proportion of publications in the various scientific fields is published in journals with impact factor above the median and mean values of the distribution of journal impact factor?
  
  
  METHODS
  We analyzed and compared the distribution of the impact factor data reduced to the unit of science publication, the article. We calculated the proportion of articles published in journals with impact factor above the journal mean impact factor, journal median impact factor, and article mean impact.
  
  
  RESULTS
  For all categories examined, at the article level, the mean impact factor was higher than the median (by 13.7% to 500% for the various scientific categories). The mean impact factor of journals was considerably lower than the mean impact factor of articles (by 0.3 to 6.4 units). The proportion of articles that were published in journals with impact factor above the journals' median impact factor was well above 50% in 17 of 19 scientific fields examined (all except mathematics and computer science).
  
  
  CONCLUSIONS
  Our analysis shows that in most scientific fields examined, it is quite easier to publish an article in the top 50% of journals (based on impact factor calculations) than it is for the article to be included in the top 50% of published articles (based on the assumption made regarding the article' impact factor).
authors.affiliation: Alfa Institute of Biomedical Sciences, Marousi, Greece. m.falagas@aibs.gr
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Falagas
authors.forename: Eustratia
authors.initials: E
authors.lastname: Charitidou
authors.forename: Vangelis G
authors.initials: VG
authors.lastname: Alexiou
mesh_terms: D015706:Bibliometrics; D010506:Periodicals as Topic / Q000706:statistics & numerical data*; D011643:Publishing / Q000706:statistics & numerical data*; D012106:Research / Q000706:statistics & numerical data; D012107:Research Design; D012586:Science / Q000706:statistics & numerical data*