Duplicate (library)
A doublet , or doublet ( CH ) or a multiple-copy (also double piece ) is in librarianship an award in the library collection available medium (eg. As book, magazine, CD, DVD). Furthermore, catalogs that exist several times ( data records in library catalogs ) are referred to as duplicates.
Duplicates in inventory
The acquisition of multiple copies is often wanted; especially with media that are in high demand, such as textbooks in a textbook collection . In the case of standard works such as dictionaries , one of the copies can often not be borrowed as reference inventory. If the content of a work that is available in several copies for these reasons is overtaken by a revision, the reason for making several copies available no longer applies, as the newer version is now more important in use, while the older version is only of documentary interest. This eliminates the need for multiple copies.
Duplicates can come into the possession of a library through donations , bequests or the takeover of other library holdings, especially if the content of the source was similar to that of the receiving agency, e.g. if the estate of a theologian is given to a theological library or a monastery library to a theological library Institute passes.
In the case of the de- assignment of duplicates that are no longer required, these other libraries can be offered (duplicate exchange). However, this practice is no longer so common, since from a business point of view the administrative effort can exceed the benefit. In addition, standard works are often already available in the libraries in question as buyers. In such cases, checking the condition can be relevant, ie the better preserved specimen is kept, the worse one is eliminated. However, due to the administrative burden, this can also be dispensed with. In this case, the rejected duplicates are rejected or sold, the latter either to an antiquarian bookshop or to the library users. This does not apply to archive libraries, which are not allowed to separate any holdings.
The usual rules of deduplication cannot be applied to historical book holdings (e.g. of incunabula , prints from the early modern period, but also from later periods) because, due to specimen- specific characteristics, for example in provenance research , book studies , binding research or for similar research interests, each individual copy can be understood as unique and therefore no duplicates exist. In a broader sense, this also applies to all other books with ownership notes and comments.
Duplicates in catalogs
While the distinction between individual copies in the catalog is intentional - for example for the administration of the loan - the information at the level of the edition and the work should be merged as far as possible within the framework of the Functional Requirements for Bibliographic Records (FRBR). Duplicate or multiple data records can arise unintentionally if data from different sources are merged or if an existing data record is not recognized when a new data record is created. Many library systems have duplicate detection methods to detect duplicates . This prevents the administration of multiple copies and the new entry of an already inventoried copy. The combination of different sources where duplicates can occur, occurs in librarianship in areas such as digitization of old catalogs ( tape catalogs , index cards , etc.), in the data transfer to union catalogs and metasearch engines on.
With the so-called "matchkey", a method for calculating a hash value for bibliographic data sets is to be developed at German libraries in order to find duplicates.
swell
- ↑ Susanne Oehlschläger (Minutes): Report from the 49th meeting of the Working Group of Verbundsysteme on November 23 and 24, 2005 in Cologne . German National Library, p. 1 ( PDF ).
literature
- Alice Keller: Deduplicate. The art of downsizing . In: Medicine - Library - Information, 4th year (2004), H. 2, S. 16 ( PDF )