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More on Impact Factors

Castelnuovo, Gianluca

doi: 10.1097/EDE.0b013e3181812c02
Letters to the Editor

Instituto Auxologico Italiano IRCCS and Catholic University of Milan; Milan, Italy

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To the Editor:

As discussed in the May 2008 issue of Epidemiology and in other recent publications,1,2 good alternatives to the Impact Factor (IF) algorithm are needed. The Thomson Impact Factor represents a limited measure of the importance of an individual article, as 80% of a journal's IF is determined by only the 20% of the papers published. In the past few years, several new indexes has been created to provide alternatives to the IF algorithm. These include the removal of self citations from the calculation of the IF; using the Adjusted Impact Factor (counting a weighted sum of citations per month over a time period of 4 years); and other modifications (Cited Half-Life Impact Factor, Median Impact Factor, Disciplinary Impact Factor, and Prestige Factor). There is also the Euro-Factor, born in Europe to avoid the strong US-centricity, and the English language basis of the Thomson database.

One possible strategy to avoid “IF supremacy” is to create a new index, the Single Researcher Impact Factor, that would move the evaluation from the power of scientific journals to the quality of single researchers. This measure can take into account number and quality of the traditional publications and of the other activities usually associated with being a researcher, such as reviewing manuscripts, producing guidelines, writing clinical manuals, and planning congresses and meetings. Also, in funding policy, it might be more useful to consider the merits, contributions, and real impacts of all the scientific activities of each single researcher, instead of measuring or adding only the journals’ IF numbers.

Some experimental versions of this new index are under evaluation in economics3 and clinical psychology.4

Gianluca Castelnuovo

Instituto Auxologico Italiano IRCCS

and Catholic University of Milan

Milan, Italy

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1. Castelnuovo G. Time for the single researcher impact factor. BMJ. 2008;336:789
2. Brown H. How impact factors changed medical publishing and science. BMJ. 2007;334:561–564.
3. Tucci P, Fontani S, Ferrini S. L'R-factor: un nuovo modo di valutare la ricerca scientifica. Quaderni del Dipartimento di Economia Politica. 2008;527:1–38.
4. Molinari E, Castelnuovo G. La valutazione della produzione scientifica in psicologia clinica: impact factor e prospettive integrative. In: Molinari E, Labella A, eds. Psicologia Clinica: Dialoghi e confronti. Milan: Springer; 2007:203–215.
© 2008 Lippincott Williams & Wilkins, Inc.