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Posted on Wednesday August 30, 2017

Updated on Monday November 6, 2023

Section 3 - Transforming MARC21 to EDM

This section is highlighting how the library domain professionals look at developing and applying transformation to their specific library format, MARC 21, how that translates into EDM and further beyond how it is presented on the Europeana website.

main image
Title:
The Riva Sisters Jugglers
Institution:
Circus Museum

So you have a fine set of MARC21 records? Let's find out how to produce an even nicer set of EDM records out of them!

Lesson 9 - Introduction from MARC21 to EDM

In 2011, a group of library professionals gathered to discuss how the Europeana Data Model fit library data needs. The group wanted to understand how a mapping of traditional library metadata records correlated to the three principle EDM structures (edm:ProvidedCHO, edm:WebResource, ore:Aggregation).

Since EDM is an RDF-based model, the records had to be viewed as being made up of a set of separate statements which could then be redistributed across the EDM classes. In order to support this process, a model was created defining which EDM classes would be used in the library context, the relations between them, and the EDM properties chosen to describe these relations. Europeana is currently implementing only a subset of the EDM properties defined in the main EDM specification. In this course, we’ll focus mainly on the Europeana Data Model for monographs.

In the traditional library world, the description of objects (books, journals etc.) is record-based. Such a record, which can be seen as a closed box, is a defined set of description elements that can include information about:

  • The real world object or item, - the book on a shelf
  • The bibliographic object - the edition representing the entirety of all identical copies of a publication
  • The digital representation of the real world object - a digital copy of the book
  • The record itself - information about when the record was created and by whom.

In contrast to this closed box model, the Europeana Data Model is a statement-based model - the description of library objects covers separate entities and their relationships on different abstract levels. In this world we therefore differentiate between:

  • The description of the information - the entirety of all identical copies of a book - and the information carrier - the book on the shelf.
  • The description of the real world object - the book - and its digital representation - a digital copy of this book.
  • The description of the object described - the book - and the object describing it - the metadata.

And we interlink these entities and express these links with RDF statements.
Mapping a traditional metadata record to EDM therefore means that the closed box has to be opened, the record will be taken apart and the different entities described in one record will be identified as EDM classes and related to each other.

For more details please read the deliverable of the Europeana Libraries project.

Lesson 10 - Recap for the EDM core classes

The following is a quick recap on the core classes of EDM.

The edm:ProvidedCHO is the cultural heritage object which has given rise to and is the subject of the package of data that has been submitted to Europeana. Its properties are those of the original cultural heritage object. Strictly speaking, the edm:ProvidedCHO is the resource in Europeana that relate to the original cultural heritage object not its digital representation, for example attributes of the Mona Lisa, not the digitised image of the paintining.

EDM defines edm:Web Resource as ‘information resources that have at least one web representation and at least a URI.’ In this model, the edm:WebResource is a digital representation of an item (e.g. of a printed resource or a born-digital resource). All information about a representation – whether it is born-digital or digitized – has to be provided using  an instance of the class edm:WebResource.

The ore:Aggregation serves to group together all important elements of cultural heritage objects contributed by the content providers. Aggregations are used in EDM to represent the complex constructs that are provided by contributors. In compliance with EDM, the fundamental relationships between edm:WebResource and edm:ProvidedCHO are realized by using the ore:Aggregation class. This is the place where the metadata relating to this whole object will be recorded

As mentioned throughout this course, all the classes and properties, the data types that can be used as values and the obligation level of each property are described extensively in the EDM Mapping Guidelines. These guidelines are to be found on the Europeana Data Model Documentation page and should serve as guidance for providers wanting to map their data to EDM. Those interested can find there an example of original data, the same data converted to EDM and diagrams showing the distribution of the properties amongst the classes. The mapping guidelines should be consulted frequently as the full set of EDM classes and properties are being implemented incrementally.

Next, we'll present a mind map of actual MARC21 fields that could be assigned to respective EDM fields and classes. Following that we have a practical example from the National Library of Serbia of creating EDM from their MARC21 records. At the end of the section, we'll take to a more visual trip to see how an object from a library shelf becomes a presence in Europeana.

Please note, that the examples presented here are to serve as guidance and support, and might not always match your data manipulation needs.

Mind mapping MARC21 to EDM

Case study 1 - MARC21 to EDM Practical mapping

Presentation on practical mapping exercise from Petar Popovic, National Library of Serbia

When mapping, libraries can use different tools that allow data manipulation. In this section, Petar Popovic from National Library of Serbia presents his practical experience.

Conclusions from the presentation:

  1. Tools /systems used to do transformation from MARC to to EDM:  Notepad++ as text editor and it's "XML tools" plug-in (free opensource software).
  2. Actions they took in performing this task:  reading EDM Mapping Guidelines and related documentation, writing of the xsl template that produces EDM structure from MARC21 and  that calls other matching templates for each EDM field; consulted to the MARC manual for matching fields, loaded the marc xml data into the tool, execute xls transformation, and receive the EDM output.
  3. Issues encountered related to the characteristics of MARC and EDM specification: some data fields in MARC might not have equivalent in EDM, adding the xml:lang attribute sometime conflicts with the values in the catalogued data, ie in MARC there is no attribute of the datafield element that tells in which language is the element’s value given
  4. Lessons learned: fun to play around with XSLT, but a good tool/method should be provided to support data manipulation for library professionals that are not familiar with hard coding

Case study 2 - From a poster on a library shelf to a record in Europeana

To conclude our course, we are now taking you on the journey an object has to make before it appears on the Europeana website.

This lesson explains how the metadata for a playbill of the Debrecen Theatre are catalogued and captured in MARC21. It then illustrates the mapping to EDM and the transformation of that EDM record during the publishing process. At the end, you will see where in the Europeana website you can find the various elements that were created during the digitisation, cataloguing, mapping and transformation process of that playbill.

If you are interested in looking at the chosen object more closely, you can find it in the Europeana website and you can also see the raw metadata (MARC21, EDM, EDM enriched).

Reading

Acknowledgements

This online course on EDM would not have been possible without the guidance and inspiration of the following contributors:

Valentine Charles, Cécile Devarenne (Europeana) -  In house EDM gurus

Antoine Isaac, Nuno Freire (Europeana) - EDM cheerleader and Libraries Data aficionado

Uldis Zariņš (National Library of Latvia), Henning Scholz, Pierre-Edouard Barrault and Adina Ciocoiu (Europeana) - Content creators

Uldis Zariņš (National Library of Latvia), Pierre-Edouard Barrault, Maike Dulk (Europeana) - Video editors

Petar Popović (National Library of Serbia)  - Case study contributor & EDM lab mouse

Beth Daley (Europeana) - Text proofreading

Thank you very much for your support and participation!

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