The case for a citation index by the humanities, for the humanities

Citation indexes are by now part of the research infrastructure in use by most scientists: a necessary tool in order to cope with increasing amounts of scientific literature being published. Commercial citation indexes are designed for the sciences and have uneven coverage and unsatisfactory characteristics for scholars in the humanities, while no broad-coverage citation index is proposed by a public organization. We argue that a citation index for the humanities is desirable, for four reasons: it would greatly improve the retrieval of sources, it would offer a way to interlink collections across repositories (such as archives and libraries), it would foster the adoption of metadata standards and best practices by all relevant actors (including libraries and publishers) and it would contribute data to fields such as bibliometrics and science studies. We also suggest that this citation index must be informed by a set of requirements relevant to the humanities, including comprehensive source coverage and substantial chronological depth. To substantiate our proposal, we showcase two infrastructure components of the envisaged humanities citation index: a prototype online application including a digital library and citation index for the historiography on Venice (named Venice Scholar), and two open linked data citation repositories made available by OpenCitations (i.e. the OpenCitations Corpus and the Crossref corpus COCI). The Venice Scholar digital library allows operators to curate machine-extracted citation data, which will then be federated by OpenCitations into its persistent triplestores of citation data. These citation data can be pulled and served via the Venice Scholar citation index: an open online application. We conclude by proposing that the humanities citation index should be created taking a collaborative, distributed and open effort, as made possible by the proposed infrastructure: taking inspiration from library catalogs and in collaboration with GLAM institutions, primarily libraries.