Yves Genras is a professor at the University of Quebec in Montreal, one of the founders and scientific director of the Canadian Observatory of Sciences and Technologies. This book provides a retrospective look at the successes and failures of scientometric projects related to the assessment of scientific activity, the use of citation databases and benchmarking. The author sets out in a concise and accessible form the logic, history and typical errors in the use of these tools. His position: despite the obvious analytical value of scientometrics in conditions of rapid growth and differentiation of scientific fields, attempts to apply it to assessing the performance of individual scientific institutions over short time intervals almost inevitably lead to manipulation of scientometric indicators aimed at artificially inflating positions in rankings. The main text of the book is supplemented by a new article by Gengr with a similar topic and an essay, co-authored with Olesya Kirchik and Vincent Larivière, on the level of visibility of Soviet and Russian scientific publications in the international citation index Web of Science. The publication will be of interest to both scientific administrators and scientists who are in a situation of reform of the system for assessing scientific effectiveness.