The amount of gray literature, understood as the accumulation of scientific material that has not been refereed in the traditional way and is not at the reach of scientists everywhere, is immeasurable.

Under the name of gray literature are included thesis, dissertations and promotion papers of all levels of higher education, technical or institutional reports and local periodical publications of null or poor distribution generally, but not always, written in languages different from English, which has become the universal language of science. There is abundant gray literature in all the countries of the world, whether developed or not.

Traditionally, the concept of gray literature is opposed to that of papers published in science journals, be the so-called mainstream journals or not, that appear periodically and fulfill the righteousness, objectivity, quality and availability expectations of the academic community. Nowadays, with the general dissemination and availability of electronic media, the panorama is subjected to important changes. There are very serious initiatives for dissemination of scientific information outside the traditional media, for the steps of pre-publication, open refereeing, publication and post-publication discussion. There are local and national information repositories that are universally accessible in internet.

On the other hand, the generalized acceptance of the impact factor and its quasi-monopoly in the hands of the Institute of Scientific Information have been questioned. Parallel publication validation systems have been established at the local, national and regional levels. To a good extent, this has been the result of the implementation of institutional or national recognition systems for salary compensation of the work of researchers and teachers.

If at the start the existing amount of gray literature was deemed immeasurable, that which is not worth rescuing, for not representing any contribution of a novel character, utilizable or deserving to be read even at a local level, is equally immeasurable. Nevertheless, it is also undoubtedly abundant that information which should de recovered and made accessible to the scientific community.

The biggest difficulty to achieve a validation of the existing gray literature is to establish criteria, certainly necessary, to admit or reject a given material and then incorporate what is selected in appropriate data bases with indexed catalogues that permit the utilization of at least a good part, even if not all of the material. Such validation will require an immense multidisciplinary effort and great objectivity. But it is feasible.

The information is so huge that it would seem not to make any sense to undertake the needed evaluation of all the existing material. However, it is necessary to take into account the implementation of interesting and fruitful initiatives carried out with the purpose of systematizing and classifying the existing quantity of gray literature by specific areas of knowledge, such as the case, for instance, of food sciences. It is imperative to carry out a great effort on the part of institutions, governments and international organizations, as well as of private foundations, so as to achieve real progress in the evaluation, rejection (why not?), classification, storage and dissemination of gray literature.

Miguel Laufer, Editor, Interciencia