Journal self-citation on the h5-index of Ibero-American journals

Abstract: It aims to analyze journal self-citation in Ibero-American journals from the h5-index of the Google Scholar Metrics. The bibliometric tool Gsm_hdata was used to identify 4049 Ibero-American journals indexed simultaneously in Latindex and Google Scholar Metrics. Self-citations were identified, self-citation rates by country and research area were calculated, and the h5-index was recalculated without self-citations (hs5-index). No self-citations were identified in almost 40% of the journals, especially those with an h5-index lower than 5. The overall average self-citation rate was 3.6%. Among the 1859 most cited journals with at least one self-citation, the rate was 4.8%, lower than that of research based on the Impact Factor. Journals of Engineering, Exact and Natural Sciences, and Agricultural Sciences had the highest self-citation rates, while Social Sciences and Humanities journals presented the lowest. Journals with excessive rates (outliers) were identified in all areas. These results suggest that the prior exclusion of journal self-citations in the calculation of the h5-index is not necessary. However, monitoring journals with excessive self-citation rates is recommended to avoid distortions in impact assessment procedures based on h5-index of Google Scholar Metrics.