Linked Heritage Glossary

Linked data is a pattern for hyperlinking machine-readable data sets to each other using Semantic Web techniques, especially via the use of RDF and URIs. Enables distributed SPARQL queries of the data sets and a browsing or discovery approach to finding information (as compared to a search strategy). Linked Data is intended for access by both humans and machines. Linked Data uses the RDF family of standards for data interchange (e.g., RDF/XML, RDFa, Turtle) and query (SPARQL). If Linked Data is published on the public Web, it is generally called Linked Open Data (See: W3C Government Linked Data Working Group: Linked data Glossary).

Explore further the Linked Heritage learning object: Linking Cultural Heritage Information.

See also: Linked open data, Linking open data cloud, Resource Description Framework (RDF), Semantic Web

The Linked Heritage aggregation includes data from archives, museums, libraries, research centres and universities (see: Linked Heritage partners and contributors), and covers 3D models, manuscripts, ancient prints, medieval antiquities, archaeological artefacts, monuments, Greek and Latin inscriptions, fossils, ancient and modern paintings, ethnographic collections and more. According to Europeana blog, the Linked Heritage aggregation is one of Europeana's biggest aggregators.

Linked open data (LOD) is a growing movement for organisations to make their existing data available in a machine-readable format. This enables users to create and combine data set and to make their own interpretations of data available in digestible formats and applications. LOD is all about opening up information and data as well as making it possibile to use and reuse it.

LOD is domain-independent.

LOD drive the following 10 principles:

1.: Data must be complete

2.: Data must be primary

3.: Data must be timely

4.: Data must be accessible

5.: Data must be machine-processable

6.: Access must be non-discriminatory

7.: Data formats must be non-proprietary

8.: Data must be license-free

9.: Permanance

10.: Usage costs

The 5 stars by Sir Tim Berners-Lee:

1.: Information is available on the Web (any format) under an open license

2.: Informationis available as structered data (e.g. Excel instead of an image scan of a atable)

3.: Non-proprietary formats are used (e.g CSV instead of Excel)

4.: URI identification is used so that people can point at an individual data

5.: Data is linked to other data to provide context.

Data represent "things" (known as resources) that can can be anything, including: objects, archival material, books and other document types, media files, places, persons, and organisations, events and concepts (such as material, colour, and style). RDF is the standard in linked data used to describe the "things".

Explore further the Linked Heritage learning object: Linking Cultural Heritage Information.

See also: Linked data, Linking open data cloud, Resource Description Framework (RDF), Semantic Web

Linking open data cloud is a group that catalogs data sets that are available on the Web as Linked Data and contain data links pointing at other Linked Data sets. These data sets have been published as Linked Data by contributors to the Linking Open Data community project and other individuals and organisations. The catalog of the LOD cloud data sets is hosted by Datahub, the free, powerful data management platform from the Open Knowledge Foundation, based on the CKAN data management system. It is used to generate the Linking Open Data Cloud diagram maintained by Richard Cyganiak (DERI, NUI Galway) and Anja Jentzsch (HPI). The LOD cloud data set catalog is also used to generate the statistics provided in the State of the LOD Cloud document.

Currently the LOD Cloud consists of 340 data sets.

Explore further the Linked Heritage learning object: Linking Cultural Heritage Information.

See also: Linked data, Linked open data

Machine-readable is defined by  the Government Performance and Results Act (GPRA) as any "format in a standard computer language (not English text) that can be read automatically by a web browser or computer system. (e.g.; xml)."

Machine-readable data is data (or metadata) which is in a format that can be understood by a computer. There are two types: human-readable data that is marked up so that it can also be read by machines (examples; microformats, RDFa) or data file formats intended principally for machines (RDF, XML, JSON).

Publishing public data in an open, standard, machine-readable format is a best practice (good operating practice).

Explore further the Linked Heritage learning object: Linking cultural heritage information.

See also: Data, Linked data, Linked open data, Metadata, Semantic Web

A procedure where elements in a structured data set (e.g. in a metadata schema) are linked to elements in another data set. It is supported by crosswalks that provide a mapping of metadata elements from one metadata schema to another. Supporting the ability to retrieve the same or similar content in different data source, crosswalks support the so called semantic interoperability.

The Linked Heritage Technology Platform, MINT, implements an aggregation infrastructure offering a crosswalk mechanism to support the following critical activities:

• harvesting and aggregating metadata records whether by standard and proprietary schemas
• migrating from content providers' model to a reference model
• transforming records from the Linked Heritage model to the Europeana Semantic Elements (ESE) and the Europeana Data Model (EDM).

Explore further the Linked Heritage learning objects: MINT Services and Terminology.

Metadata is structured information that describes, explains, locates, or otherwise makes it easier to retrieve, use, or manage an information resource. Metadata is often called data about data or information about information. According to Tim Berners-Lee's axiom "metadata is data".

The term metadata is used differently in different communities. Some use it to refer to machine understandable information, while others use it only for records that describe electronic resources. In the library environment, metadata is commonly used for any formal scheme of resource description, applying to any type of object, digital or non-digital. There are three main types of metadata: descriptive metadata, structural metadata and administrative metadata, each of them contributing to the management of information resources and help to ensure their intellectual integrity both now and in the future (See: NISO, Understanding Metadata 2004).

In the context of the Linked Heritage Aggregation, metadata describe digital objects of one of the type accepted by Europeana that will govern which facet they appear under in the portal:

• text (books, letters, archival papers, dissertations, poems, newspaper articles, facsimiles, manuscripts and music scores)

• image (paintings, drawings, prints, photographs, pictures of museum objects, maps, graphic designs, plans and musical notation)

• sound (music and spoken word from cylinders, tapes, discs and radio broadcasts)

• video (films, news broadcasts and television programmes) and

• 3D (virtual 3D representations of objects, architecture or places).

Explore further the Linked Heritage learning object: MINT Services.

See also: Aggregation, Content, Data, Data Exchange Agreement (DEA), Mapping

MINT: Metadata Interoperability Services composes a web-based platform that was designed and developed to facilitate aggregation initiatives for cultural heritage content and metadata in Europe.

It functions as a server for content ingestion and is based on open source software developed by the National Technical University of Athens (NTUA) in the context of the ATHENA project. MINT allows content providers to upload, map, validate and deliver metadata to be sent to Europeana in an only web environment. The platform also provides a management system both for users and organisations that allows the deployment and operation of different aggregation schemas with corresponding user roles and access rights.

Explore further the Linked Heritage learning object: MINT Services.

An ontology is a formal representation of a set of concepts within a domain and the relationships between those concepts. Ontologies are the main kind of resource used for the Semantic Web or knowledge management as a knowledge representation. The concepts are linked together by hierarchical relationships in one hand and semantic relationships in another hand (See: Athenawiki - Definitions).

Explore further the Linked Heritage learning object: Terminology.

See also: Semantic Web, Terminology, Web Ontology Language (OWL)

The Open Archives Initiative Protocol for Metadata Harvesting, commonly referred to as OAI-PMH or OAI protocol, is a protocol defined by the Open Archive Initiative. It provides a method for data providers to make records for their items (as a means of exposing metadata) available for harvesting by service providers that operate through a harvester.

Explore further the Linked Heritage learning object: MINT Services.

See also: Harvesting, MINT