Measuring scientific output of researchers by t-index and Data Envelopment Analysis

There is a growing need for ranking universities, departments, research groups, and individual scholars. Usually, the scientific community measures the scientific merits of the researchers by using a variety of indicators that take into account both the productivity of scholars and the impact of their publications. We propose the t-index, the new indicator to measure the scientific merits of the individual researchers. The proposed t-index takes into account the number of citations, number of coauthors on every published paper, and career duration. The t-index makes the possible comparison of researchers at various stages of their careers. We also use in this paper the Data Envelopment Analysis (DEA) to measure the scientific merits of the individual researchers within the observed group of researchers. We chose 15 scholars in the scientific area of transportation engineering and measured their t-index values, as well as DEA scores.