Can Impact Factor data be trusted?
Journal impact factors have a crucial role, either positive or negative, in establishing the status of a journal and the perceived importance of papers that these journals publish. Two recent editorials1, 2 call into question the integrity of the data used by the Thomson Corporation to calculate impact factors. The author’s concerns include the lack of verification of the primary data, apparent inconsistencies between official impact factors and the posted citation data, errors in the calculations of the total numbers of papers in journals and the categories in which they are placed, and Thomson′s customer service. We are not able to offer any insight into verification of the data collection; however, we do wish to comment on the other issues.First, we have used the Web of Science® on the ISI Web of KnowledgeSM site to verify the impact factor of our own journal, Lab Invest, and have found the citation data to be accurate. Second, the article count used for the calculation of the Lab I