Selection
Leiden University Library collect in close collaboration with researchers and lecturers.
Subject librarians, curators, and medical information specialists collect based on collection formation profiles. A collection formation profile describes the subjects on which purchases are made. The profiles are created in close consultation with the scientific staff of research institutes. They are regularly adjusted in consultation with researchers and lecturers so that the collection specialists can anticipate current and changing needs in research and education.
Collection formation focuses on ensuring a high-quality core collection of "just-in-case" materials (potentially valuable material), supplemented with "just-in-time" purchases (based on a current need). An example of "just-in-time" is providing access to large collections of e-books in collaboration with academic publishers, after which purchases are made based on usage figures ("evidence based acquisition").
Quality
When assessing a book or journal, factors such as the author's reputation, academic affiliation, publisher, editors, enduring value, research funder, and bibliographic listings are considered first. The Leiden University Libraries also regularly purchase non-scientific material, for example when it is considered a source for research.
For online databases, not only is the content important, but also the interface. This has to be accessible, easy to use, and preferably offer options like saving and exporting to reference managers. For electronic journals and books, licensing terms are a key factor, for instance regarding options for downloading and printing (Digital Rights Management), access to journals and books in the event of a termination of the subscription (perpetual access), and agreements regarding price increases.
Language
To support widespread use of the Leiden University Libraries collections, preference is given to acquiring specialist literature in Dutch and English. Primary sources are preferably purchased in the original language. Some collection development profiles support the collection of materials in a wide range of languages to support degree programmes and research programmes, for example in the field of area studies.
Format
Paperbacks or hardbacks: when both are available, hardbacks are preferred for sustainability. However, if the price difference exceeds 25 euros, the paperback is purchased instead.
Ebooks and ejournals: when a book is available in different formats, an ebook is preferred, except when an ebook is substantially more expensive than a printed copy or when a paper copy is more convenient to use, for instance when reading long texts.
Electronic books and journals are made available through subscriptions to packages or by purchasing individual titles or packages. Packages are purchased both directly from publishers (such as Springer, Brill, and Oxford University Press) and via ebook aggregators (such as EBL and EBSCO). Although ebooks are not necessarily cheaper than a hard copy, they can be useful when multiple users need to access a publication simultaneously.
Journals are preferably purchased e-only, instead of in print or hybrid form. For reference works, such as dictionaries, bibliographies, and indexes, the first choice is also digital due to ease of access and searchability.
Discard Policy
Decisions to remove specific materials from the collections are made in the context of the collections as a whole. Removal of materials is considered, for instance, in the case of unnecessary duplicate copies or when a print version of an electronic journal is still available. In the latter case, the electronic version must be stored securely and reliably in the long term and be of high quality. Additionally, at least one print copy must remain available in one of the Dutch University Libraries.