A Relative Authorship Index: A New Metric for Evaluating Individual Contribution in Scientific Research

Area of Science:

• Bibliometrics
• Scientometrics
• Research Assessment

Background:

• Traditional bibliometric indicators (e.g., publication counts, h-index) can overestimate researcher productivity due to unaddressed authorship inflation.
• Failure to account for the number of co-authors or inflated authorship skews conventional productivity metrics.

Purpose of the Study:

• Introduce the Relative Authorship Index (RAI), a novel metric to correct for authorship inflation in bibliometrics.
• Develop a field-specific method to identify and quantify potential authorship inflation.
• Propose an authorship correction formula to adjust existing bibliometric indicators.

Main Methods:

• The Relative Authorship Index (RAI) compares the number of co-authors on a publication to the number of authors in its cited references.
• This field-specific baseline identifies publications with unusually high co-authorship counts.
• An authorship correction formula was developed, penalizing inflation based on RAI and author position (first, last, corresponding).

Main Results:

• Application to neuroscience articles from Italian universities revealed significant regional and university-specific differences in authorship inflation.
• Higher RAI values were observed in southern regions and at private universities.
• A case study demonstrated the index's ability to capture variability in authorship practices among individual researchers within a department.

Conclusions:

• The Relative Authorship Index (RAI) offers a more accurate measure of research productivity by accounting for authorship inflation.
• The proposed correction formula can refine bibliometric indicators for more equitable research assessment.
• Findings highlight the need to consider authorship practices in the evaluation of scientific output.