  As it happened in all domains of human activities, economic issues and the
increase of people working in scientific research have altered the way
scientific production is evaluated so as the objectives of performing the
evaluation. Introduced in 2005 by J. E. Hirsch as an indicator able to measure
individual scientific output not only in terms of quantity, but also in terms
of quality, h index has spread throughout the world. In 2007, Hirsch proposed
its adoption also as the best to predict future scientific achievement and,
consequently, a useful guide for investments in research and for institutions
when hiring members for their scientific staff. Since then, several authors
have also been using the Thomson ISI Web of Science database to develop their
proposals for evaluating research output. Here, using a software we have
developed, we analyse more than 100 thousand articles and show that a subtle
flaw in Web of Science can inflate the results of info collected, therefore
compromising the exactness and, consequently, the effectiveness of Hirsch's
proposal and its variations.
