H-Index Has More Than Quantity (Publication Productivity) And Quality (Citation Impact) Nomological Dimensions

Abstract

Of all the bibliometric parameters, the h-index is the most widely used to gauge the academic productivity and contribution to disciplines. In 2005, Hirsch proposed the h-index as a robust indicator of the quantity (number of publications) and quality (impact of the citations) of a scientific publication, but this speculation has not been empirically tested. This investigation determined the contributions of quantity and quality dimensions to the prediction of h-index and identify which of the dimension is the most viable in predicting it. The h-index, total number of publications, citation, and co-authorship counts for the 80 medical and health sciences fellows of the African Academy of Sciences were obtained from the Scopus database. The h-index is significantly related to publication (r = .388, p<.001), citation (r = .309, p<.01) and co-authorship (r = .246, p<.05) counts. The three independent variables combined significantly predicted h-index (F (3, 76) = 4.68, p<.01, R² = .156). Although the regression model is a good fit for the data, only 15.6% of the variance in h-index was accounted for by the three bibliometric parameters. Publication count is the only viable predictor, explaining 15.1% out of the 15.6% total variability in the h-index. The remaining 84.4% variance that is unexplained in this study suggests that h-index has more than the quantity and quality nomological dimensions. Follow up studies should explore the predictive viability of other bibliometric measures such as the number of “reads,” book and chapter authorships, invited presentation engagements and conference proceedings.