To appreciate what a huge difference there is between the author of a peerreviewed journal article and just about any other kind of author we need only remind ourselves why universities have their "publish or perish" policy: aside from imparting existing knowledge to students through teaching, the work of a university scholar or scientist is devoted to creating new knowledge for other scholars and scientists to use, apply, and build upon, for the benefit of us all. Creating new knowledge is called "research", and its active use and application are called "research impact". Researchers are encouraged, indeed required, to publish their findings because that is the only way to make their research accessible to and usable by other researchers. It is the only way for research to generate further research. Not publishing it means no access to it by other researchers, and no access means no impact ­ in which case the research may as well not have done in the first place.

In the midst of a debate on access to information, the World Health Organization and the FAO have decided to develop a strategy to guarantee the right of poor countries to have free access to scientific publications. This right is often denied, mainly because of high subscription costs. For this reason, universities and research centres in southern countries must forego buying magazines, which are a valuable instrument for updating, and exchanging information on research and scientific issues. This choice has been made in an historical period when the industrialized world is marked by a knowledge-based economy.

Some recent events have brought to the attention of the general public the issue of free access to scientific information. On many occasions basic scientific information has been said to be constantly available to scientists. In truth, a group of scientists (those who live in the developing countries) have long remained on the fringes of the international research community and in part still are, mainly because of the existing difficulties in accessing scientific publications. However, this fact has never been as blatant as it was with the Human Genome Project. Indeed, the project saw an attempt to conceal and privatize the results of advanced basic research. On that occasion, the fear of a private exploitation of scientific results became a real threat.

Science was born when knowledge was no longer kept secret and became public. Its development is inextricably tied to the possibility that researchers continue to share the results of their discoveries as easily as possible. These are the points on which the concept of access to scientific information is based and on which the scientific community has founded its model of communication. However, there are currently numerous obstacles, mostly economic, preventing researchers from being real actors in the creation, control and verification process of scientific knowledge. Despite the technologies made available by the Internet, free access to scientific information continues to be limited by the cost of magazines and the opposition by the publishers. Hence, scientists have promoted an increasing number of initiatives with a view to re-confirming the principles of open access.

There are forces, factors, and influences other than pending classical peer review that assure the quality of scholarship before formal publication.

Peer review is the evaluation method that has characterized the scientific growth of the last four centuries, the first four of what is called modern science, indeed. It is matter of scientific communication inside scientific community, a subject too poorly studied in comparison with its critical importance for a scientific study of science (science of science). Peer review has been used for scientific paper evaluation before publication (editorial peer review) and for research proposal evaluation before financial support (grants peer review). Both cases present similar pros and cons, so I will treat them as a unique method for scientific evaluation. While the method remained pretty unchanged all along the period, apart from communication technology with peers, science has tremendously changed its organization and its relevance to society. So, peer review is antique and well rooted in practise, but its historical aim should now to be contrasted with the present situation of actual research, practises and social involvement of science.

I still remember very clearly my first encounter with peer review: I was a Ph. D. student in physics and I had written my first paper, submitted it to a journal and - after what seemed to me a very long time - received a reply with the request for few changes and corrections I was supposed to include in my paper before it could be considered for publication. These very simple steps: the writing up of some original research results in a paper, its submission to a journal and the process of the work being read and judged by someone reputed to be an expert in the field is what we call peer review - the judging of scientific work by your peers - and it is an essential part of what science is. No scientific achievement can be considered as such until has been recognized by the community at large and such a recognition mainly comes from the peer review process. The presence of this check has arguably helped and fostered the constant and cumulative growth of science.

Scholars and scientists do research to create new knowledge so that other scholars and scientists can use it to create still more new knowledge and to apply it to improving people's lives. They are paid to do research, but not to report their research: that they do for free, because it is not royalty-revenue from their research papers but their "research impact" that pays their salaries, funds their further research, earns them prestige and prizes, etc. "Research impact" means how much of a contribution your research makes to further research: do other researchers read, use, cite, and apply your findings? The more they do, the higher your research impact. One way to measure this is by counting how many researchers use and cite your work in their own research papers.