Who controls the controllers? Ten statements on the so-called impact factor

The impact factor has become a widely used tool for the evaluation of scien tific research. It is calculated by dividing the number of citations by the source items published in the journal during the previous two years, Despi te its popularity, the parameter should be handled with care due:to the man y phenomena that influence citation rates. The correlation between the impa ct factor of a journal and the citation frequency of a single article is qu estionable. Author's selection of references is subject to factors unrelate d to quality. There is a tremendous bias towards English language journals compared to those publishing in other languages. The impact factor favours research areas that promote short-term studies, whereas a tendency to treat long-term clinical investigations as less important is simultaneously crea ted.