Nature retains its position as the most cited weekly science journal, with over 390,000 cites, an increase of almost 18,000 on last year’s count. And Nature continues to publish more articles than any other multidisciplinary journal. For 2006 Nature’s impact factor is 26.681. The impact factor of a journal is calculated by dividing
the number of current year citations to the source items published in that journal during the previous two years. It is an independent measure calculated by Thomson/ISI (Institute for Scientific Information), Philadephia, USA.