Research rating: Some technicalities.

From time immemorial, the body of scientific knowledge has grown with incremental additions of research. Metrics-based research evaluation provides crucial information regarding research credibility that would be difficult to understand by means of individual expertise. h-index and its modifications give an approximate quantitative measure of research output. Furthermore, g-index, e-index, ħ-index and i10-index address various intricacies involving authorship. Altmetrics and Plum X metrics are newer usage metrics that put an additional weightage on the impact on social media, usage, capture and scholarly networking. Indirect evaluation of research can also be obtained from the Journal Impact Factor in which the research is published but with certain limitations. While the scientific community is still waiting for a unique one-stop solution based on a high-quality robust process to exert judgement on research, the Leiden Manifesto comprising ten principles for research assessment can act as a guiding tool for development of a comprehensive evaluation system.