Quantitative analysis – counting, measuring, comparing, and analyzing quantities to "know something" – is perhaps the main tool of science today. The substance of scientific research is so complex and specialized that personal knowledge is no longer sufficient for understanding trends or for making decisions.

Bibliometrics turns quantitative analysis on itself and approaches the evaluation of research with the same basic tool – counting. Counting the number of publications and citations and understanding their trends in context is key to evaluating the impact of research. Quantitative evaluation of publication and citation data is now used in almost all nations around the globe with a sizeable science enterprise.

Download the 10 Rules for Using Publication and Citation Analysis for practical advice on how bibliometrics should – and should not – be used to judge the quality and impact of published research.