The bibliometric indicators of scientific production measure the results of the research, as published in journals or scientific books. The most used indicator is the number of papers published by an author, institution, country, journal or subject area, since it allows to know and to follow the activity from the publications. This paper presents the main bibliometric indicators of scientific production, discusses the normal productivity and fractional productivity and justifies the necessary normalization of the data mined from bibliographic databases. The need to relativize absolute indicators is explained in terms of some variables that influence their development, such as the number of inhabitants, the gross domestic product or the number of projects awarded. Finally, the main limitations of these indicators are discussed.

Bibliometrics is the use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. The interest aroused by bibliometric studies in the scientific community has been increasing, especially in the biomedical field. The objective of this work has been to address the methodological considerations to be taken into account when preparing a bibliometric study, especially those related to the knowledge of the area to be studied and the national and international bibliographic databases of data origin. The main applications of the bibliometric indicators and several examples related to Acta Pediátrica Española are described, such as the evolution of the number of articles included in Scopus, the ranking of institutions of origin, the network of cowords and some of the indicators offered by Scimago Journal & Country Rank.