A novel indicator h* to measure research efficiency and identify researchers facing challenges: Application to engineering sciences

The classical h index is a widely used metric to evaluate a researcher’s scientific impact by combining productivity and citation counts. However, its main limitation lies in its cumulative nature. Indeed, the h index never decreases, which can mask recent changes in research activity or productivity, especially in late career stages, post retirement or when researchers stop publishing and contributing to scientific work due to administrative responsibilities, a focus on teaching, exclusion from research teams or a deliberate career transition away from research. This can lead to biased comparisons between junior and senior researchers, failing to reflect current research dynamics. To address these issues, this paper proposes a new metric, the h * index, which extends the classical h index by incorporating temporal elements of a researcher career. The h * index considers active publication periods and citation rates relative to career length, making it a dynamic and updatable indicator. This allows for early detection of declining productivity, thematic isolation or shifts toward non research duties, providing a more nuanced and fair assessment of scientific performance. Moreover, given that some countries, including France, hesitate to rely solely on traditional bibliometric indices, the h * index offers a complementary tool designed for continuous career monitoring. By combining robustness and adaptability, this new metric aims to better support research evaluation and management decisions in academic institutions.