Exploring the limitations of the hindex and htype indexes in measuring the research performance of authors With the introduction of an increasing number of evaluation indexes, researchers have begun to pay attention to the limitations of such indexes in research evaluation, understanding which to avoid misusing and making evaluation more scientific and reasonable. Analysing the principles of the hindex, gindex, ARindex, pindex, integrated impact indicator (I3), and academic trace, this paper explores their limitations in measuring the research performance of authors from the perspectives of consistency, the degree of discrimination, and the statistical relationship between the values of indicators and the number of publications and citations. There are some interesting findings. These six indicators are highly consistent, and they are all more susceptible to the number of publications than to the frequency of citations. Among them, the hindex has the lowest degree of discrimination, followed by the gindex, I3, ARindex, pindex, and academic trace. The gindex ignores papers and citations other than the gcore. Moreover, compared to the hindex, the accumulation of citations makes it easier for the gindex to be equal to the number of papers published by an author, and once its value equals the number of papers, subsequent citations received by these papers will no longer contribute to the growth of the gindex unless the author publishes a new paper. Additionally, the ARindex ignores the htail papers and citations, which underestimates the impact of many researchers. Moreover, the pindex is insensitive to highly cited papers. Furthermore, the I3 is very vulnerable to the influence of the extremums in a data set. Finally, we propose considerations and suggestions for the research performance evaluation of authors.

An evaluation of research performance for different subject categories using Impact Factor Point Average (IFPA) index: Thailand case study The research performance of Thai researchers in various subject categories was evaluated using a new mathematical index entitled xe2x80x9cImpact Factor Point Averagexe2x80x9d (IFPA), by considering the number of published papers in journals listed in the Science Citation Index (SCI) database held by the Institute for Scientific Information (ISI) for the years 19982002, and the results compared with the direct publication number (PN) and publication credit (PC) methods. The results suggested that the PN and PC indicators cannot be used for comparison between fields or countries because of the strong fielddependence. The IFPA index, based on a normalization of differences in impact factors, rankings, and number of journal titles in different subject categories, was found to be simple and could be used with equality for accurate assessment of the quality of research work in different subject categories. The results of research performance were found to be dependent on the method used for the evaluations. All evaluation methods indicated that Clinical Medicine was ranked first in terms of the research performance of Thai scholars listed in the SCI database, but exhibited the lowest improvement of performance. Chemistry was shown to be the most improved subject category.