BASE – Bielefeld Academic Search Engine
BASE is one of the world’s most voluminous search engines especially for academic web resources. BASE is operated by Bielefeld University Library. BASE collects and indexes the metadata of web documents, provided via the OAI-PMH protocol. BASE provides more than 90 million documents from more than 4,000 sources. You can access the full texts of about 60% of the indexed documents for free (Open Access). The index is continuously enhanced by integrating further sources. We are working on several new features like a claiming service for authors (ORCID DE project). BASE is a registered OAI service provider. Database managers can integrate the BASE index into their local infrastructure (e.g. meta search engines, library catalogues). Further on there are several tools and services for users, database and repository managers. In comparison to commercial search engines, BASE is charcterized by the following features: 1) Intellectually selected resources; 2) Only document servers that comply with the specific requirements of academic quality and relevance are included; 3) A data resources inventory provides transparency in the searches; 4) Discloses web resources of the “Deep Web”, which are ignored by commercial search engines or get lost in the vast quantity of hits; 5) Correction, normalization and enrichment of metadata by means of automated methods; 6) The display of search results includes precise bibliographic data; 7) Display of access and terms of re-use for a document; 8) Several options for sorting the result list; 9) “Refine your search result” options (by author, subject, DDC, year of publication, content provider, language, document type, access and terms of re-use); and 10) Browsing by DDC (Dewey Decimal Classification), document type, access and terms of re-use / license. This has been added to the tools section of Research Resources Subject Tracer™ . This has been added to Academic and Scholar Search Engines and Sources white paper.