The use of research metrics is debated and can lead to pitfalls if not well understood. When deciding on whether to use a metric, always keep in mind that a holistic and multi-faceted approach to talking about research impact is the most productive. The full story of a researcher cannot be summed up in a single number.
"The problem is that evaluation is now led by the data rather than by judgment. Metrics have proliferated: usually well intentioned, not always well informed, often ill applied. We risk damaging the system with the very tools designed to improve it, as evaluation is increasingly implemented by organizations without knowledge of, or advice on, good practice and interpretation."
Hicks, D., Wouters, P., Waltman, L., de Rijcke, S, & Rafols, I. (2015). Bibliometrics: The Leiden Manifesto for research metrics. Nature 520(7548), 429-431. doi:10.1038/520429a
San Francisco Declaration on Research Assessment
In 2012 editors and publishers of scientific journals got together at the Annual Meeting of The American Society for Cell Biology in San Francisco CA and created a statement on the use of research metrics. It discusses inappropriate and appropriate uses of metrics including the journal impact factor and advocates for a holistic view of the output and value of ones scholarship.
The Metrics Toolkit website is a comprehensive list of many different research metrics and it explains how they are calculated as well as appropriate and inappropriate use cases.