Scientific performance of researchers that translates into academic improvement, tenure position in universities and project grants are commonly evaluated by using some bibliometric indicators. These indicators can be calculated through total number of papers and citations, impact factors of publishing journals, impact of each paper or impact of total papers. In addition, scientific impact of individuals is also determined by some indexes such as Hirsch (h) index. All of these measures and indexes have several limitations. Scientific projects and publications are mostly collaborative and all collaborators do not contribute to these projects and publications equally.
Thus, it is difficult to understand and analyze an individual’s performance by the outputs coming from collaborative studies. Here, a new practice for evaluating individual scientific performance is proposed. U and U’ factors are able to detect a qualified article production capacity of the scientists producing from their research projects and studies objectively. Although these factors may not give an idea about their exact contributions and solutions on the specific scientific problems, U factors will assist a more objective evaluation for individual scientific performance or productivity of the scientists than other tools such as h factor and impact factor alone. Because h factor excludes certain articles of researchers, in this paper, I propose to use U factor instead of h for a more objective evaluation. Especially the U’ factor may also be helpful for an objective selection in scientific awards, project grants and in appointing academical staff.