Elsevier today announced the highlights of its journal impact factor performance in 2008. Elsevier overall saw 75% of its journal impact factors (IF) increase from 2007 to 2008. According to the 2008 Journal Citation Report(R) published by ThomsonReuters, Elsevier journals took the #1 position in 51 categories (of 229) across all of the sciences and social sciences.

In addition, 30 Elsevier journals got their first impact factor this year. Cell Stem Cell (http://www.cell.com/cell-stem-cell/home) (16.826) entered the Cell Biology category ranked 6th (of 157 journals), while Cell Host Microbe (http://www.cell.com/cell-host-microbe/home) (7.436) entered the Microbiology category ranked 10th (of 91 journals).  Materials Today (http://www.materialstoday.com/) (12.929), which is ranked 4th in the Materials Science, Multidisciplinary category (of 191 journals).

This year there were 182 Elsevier journals that increased their impact factor by more than 50% over their 2007 scores. All three The Lancet speciality journals improved their Impact Factor this year. The Lancet Infectious Diseases (http://www.thelancet.com/journals/laninf/issue/current) increased to 13.165, placing it at the #1 position in the Infectious Diseases category. The Lancet Oncology (http://www.thelancet.com/journals/lanonc/issue/current) rose to 13.283, an increase of over 1 full IF point from the 2007 IF.  Finally, The Lancet Neurology (http://www.thelancet.com/journals/laneur/issue/current) increased by 40% to 14.270, thereby retaining the #1 position in the Clinical Neurology category for the 5th year running.

Other Elsevier journals continue their long-running trend of increased impact factors, in particular Biomaterials (http://www.elsevier.com/locate/biomaterials) (increasing yearly since 2003) and The Journal of Allergy and Clinical Immunology (http://www.elsevier.com/locate/jaci) which has shown consistent growth over the past five years.

Glen Campbell, Senior Vice President of U.S. Health Sciences Journals said, Each annual announcement of impact factors confirms the depth and excellence of our health sciences journal publishing program. The superior performance of so many of our journals this year is a sign of the strong partnerships we have with our journal editors and our societies. This year's impact factor growth is one indication of the hard work and focus on quality of these collaborations.

The fact that Elsevier's overall results are amongst the best in the industry is a true indication of the impact of the increased focus on quality we have placed on our journals in the past three years. The increased impact factors, across the board, are evidence that the research we publish is of the highest quality, remarked Martin Tanke, Managing Director of Science and Technology Journals. We are grateful for our strong network of editors we partner with, who work with us each day to build our journals to some of the best in their fields.

The impact factor is a measure of the frequency with which the average article in a journal has been cited in a particular year. The impact factor helps to evaluate a journal's relative importance, especially when compared with others in the same field.