Frequently asked questions

Linked Data is a group of technologies which enable data to be distributed and interoperable. In practical terms this means that data is hosted by separate organisations (as opposed to a centralised data silo). This data is published online in such a way that external users are able to combine it across individual host organisations in one query, thus answering questions that are impossible to answer by the data from any single host alone.


It makes sense to publish databases as Linked Data. Long-text documents can also be published as Linked Data but they are of limited benefit.


It stands for 'Universal Resource Identifier', and it is a unique address for a documentation record that we want others to refer to. The concept of ‘paper’, as defined in the Getty Arts & Architecture Thesaurus (AAT), can be referenced by the URI: ‘http://vocab.getty.edu/aat/300014109’. One of the benefit of using URIs is machine disambiguation. I.e. it is clear to a machine where to point users when a record refer to ‘paper’ according to the Getty AAT definition. Also, a URI can be matched with other words for 'paper' in different languages, thus making records language independent.


“Using Linked Data” can mean producing it or consuming it. For small sets of data, producing Linked Data could be as simple as assigning unique identifiers to records (see What is a URI?) and sharing them. Production at large scale would probably require either of the following options:

  1. Create a Linked Data database (also known as an RDF database or a triple store) where data can be inserted through forms directly in the database as Linked Data.
  2. Export the data from an existing database and convert it to Linked Data using a template and publish it on an RDF database. This can be done periodically if the underlying database is updated regularly. The template is built through a process called ‘mapping’ (sometimes it is called ‘translation’). The template takes the fields of the underlying database and ‘maps’ them to what we call an ontology (e.g. the CIDOC-CRM) which is a set of universally agreed abstract entities. For example, a database field which stores terms describing the material of objects (e.g. ‘paper’) is mapped to the CRM ‘E57 Material’ entity. The local database field is thus replaced by a universally agreed entity that everyone understands.

To consume Linked Data, one queries the RDF databases using the SPARQL query language which is a technical language. In practice, software can be produced to make such querying user friendly again through the use of forms.


Yes, an existing database can be used to produce Linked Data. The original database is not affected in this process and can remain in use (see also How do I use Linked Data?).


Yes, there are software applications that allow building new databases following Linked Data principles. ResearchSpace and Sinopia can be considered as such systems (see also How do I use Linked Data?).


A conservator can ensure that their database can be exported easily as Linked Data. This primarily means ensuring that there is a unique point of reference (a URI) for each entry in their database (e.g. instead of only storing ‘paper’ in one’s database, one can store ‘paper’ alongside its URI provided by the Getty Arts & Architecture Thesaurus ‘http://vocab.getty.edu/aat/300014109’). A conservator can search Linked Data (when available) to inform their practice based on observations made by colleagues in the past.


Yes, if it is meant to be shared as Linked Data. Free-text documents are possible to publish as Linked Data but of limited value.


Most countries apply complex copyright legislation to content. Simply uploading data on the web does not give permission for other conservators to use it in their work and share again. Choosing one of the licenses proposed in the Linked Conservation Data project means that contributors declare that they are happy for colleagues to use their data and share. The proposed license are Creative Commons zero / Public Domain and Creative Commons Attribution. The benefits of Linked Data are maximised when data is open, i.e. without any of the default restrictions for use, hence we talk about Linked Open Data.


‘Term’ refers to a word in a spoken/written language. A ‘term’ is a symbolic representation of an idea (a concept). A ‘term’ is used to communicate the idea between people who speak the same language. Many terms can be used to communicate the same idea.


A ‘label’ is a ‘term’ (see also What is a term?).


A concept is an idea which is essential for understanding documentation in conservation. Concepts are defined in thesauri. For example the English term ‘paper’ refers to the concept which in the Getty Arts & Architecture Thesaurus is defined in English as: “Refers generally to all types of thin matted or felted sheets or webs of fiber formed and dried on a fine screen from a pulpy water suspension. The fibers may be animal, such as hair, silk or wool, or mineral, such as asbestos, or synthetic. However most paper is made from cellulosic plant fiber, such as from wood pulp, grass, cotton, linen, and straw.”


A ‘scope note’ is a description of the concept that the label/term refers to. This is not a strict definition of the concept but a good enough description to encapsulate the meaning without ambiguity.


In the context of Linked Data, a namespace helps records have unique names. A namespace is a component of the URI. In a group of URIs produced as part of a dataset the shared part of the URI is often the namespace. For example all concepts of the Language of Bindings thesaurus start with "https://w3id.org/lob/" which is the namespace for the thesaurus. In Linked Data the namespace may be declared with a shortcut using the keyword prefix. For example: @prefix lob: <https://w3id.org/lob/>. The prefix lob can then be used instead of the full namespace.