Non-English journals and papers in physics and chemistry: bias in citations?

This study investigates, at the journal as well as the article level, if there is a difference in citations between English-language and non-English publications. The Web of Knowledge is used as data source. The investigation focuses on the fields of physics and chemistry. Using a precise definition of a “non-English journal”, we filter out nine physics and thirty-four chemistry non-English journals, scattered over six physics and seven chemistry subfields. Average received citations per paper (CpP) of the non-English journal(s) are compared with the CpP of pure English journals, and this in the same subfield. We clearly observe that non-English journals are inferior—in number of citations received—to pure English journals and this in all physics and chemistry subfields studied. Further, twelve physics journals and ten chemistry journals were chosen as sample journals to compare the CpP of non-English papers with that of English language papers in the same journal. The result of this comparison is that for the majority of these journals and for most of the publication years the CpP of non-English papers is lower than that of the English language papers. Finally, analyzing linguistic characteristics of the citing literature confirms the own-language preference in non-English physics and chemistry journals.