Open Linked Data Standards and Technologies: Could Linked Open Data Standards Help to Solve Problems of Current Cataloguing Practice in the Czech Republic?

SUMMARY: The study examines the possibilities of implementing linked data in Czech libraries. It analyzes the current state of processing bibliographic and authority data in the Czech Republic and proposes proce- dures for transitioning to new formats. The study emphasizes the need for modernization, which would lead to improved access to information and more efficient cooperation between libraries and other institutions. It outlines the challenges and benefits of this change for Czech librarianship.

Keywords: linked data, BIBFRAME, RDF, IFLA LRM, metadata, cataloguing, MARC format, library cooperation

This study was created on the basis of institutional support for the long-term conceptual development of the National Library of the Czech Republic as a research organization provided by the Ministry of Culture of the Czech Republic (DKRVO 2024-2028), Area 11: Linked Open Data.

Introduction

In December 2006, the Library of Congress (Washington, D.C.) established the Working Group on the Future for Bibliographic Control, led by José-Marie Griffiths (University of North Carolina, Chapel Hill). One of the Group's task was to collect new knowledge on the impact of standards for the processing of bibliographic and authority records and cataloguing procedures on the management of information resources in libraries and in their access to them in the new information and technological environment (Library of Congress, 2006).

In January 2008, the Group published an important report On the Record (Library of Congress. Working Group on the Future of Bibliographic Control, 2008). In chapter 3.1 Web as Infrastructure, the report stated that the MARC format is built on forty-year-old programming techniques and is not in line with the present day’s programming styles. The MARC format is used exclusively in the library environment and is not compatible with other systems working with bibliographic data. A broader use of bibliographic data requires a format that will accept and distinguish metadata created by experts, generated automatically, and created by users, including annotations (reviews, comments), and data on the use of the source.

Based on the recommendations formulated in this report, on October 31^st, 2011, the Library of Congress announced the Bibliographic Framework for the Digital Age initiative, or BIBFRAME (Library of Congress, 2011).^[1] The announcement of the BIBFRAME initiative was one of the important impulses in the development of new bibliographic data formats based on the RDF^[2] (Resource Description Framework) model. One of the arguments for choosing the RDF model was the fact that it is a method recommended by the World Wide Web Consortium (W3C) for conceptual description or data modeling in the Web environment.

The use of RDF and other techniques supported by the W3C consortium generally allows for better integration of data from library systems and other cultural heritage systems in the Internet environment with the aim of advanced and broader user access to information (Library of Congress, 2011). One of the main results of this initiative is the creation of an ecosystem of models, ontologies and other tools for the creation and management of linked data with the same name BIBFRAME, which is gradually being implemented in selected library databases around the world.

In addition to the BIBFRAME format, another significant achievement in this area is the development of an RDF-based RDA ontology based on the RDA cataloguing rules: Resource Description and Access – Official version . RDA Official together with BIBFRAME represent two initiatives that influence one another and are also gradually complementary, which must be seen as successors to the MARC 21 format and the RDA cataloguing rules in the Original version (currently used in the Czech Republic) for bibliographic and authority data.

How will we reaspond to this development in the Czech Republic? Is it possible to gradually change the data formats in libraries in our environment? What would be neeeded to prepare for such a change to occur?

The Goal of the Study and the Methods Used

The goal of the study is to analyse the possibilities of implementation and use of linked data formats in the environment of Czech libraries. Based on the research and analysis of sources from other countries, we will introduce the topic of linked data formats and the possible advantages of their implementation. We will evaluate the current state of processing and cooperation in the field of bibliographic and authority data in the Czech Republic with a focus on preparing data for possible conversion into linked data formats. For the research, we used mainly the analysis of bibliographic and authority data of the Czech National Bibliography. We describe the processes of processing bibliographic and authority data in the Czech Republic. We identify areas for improving and optimizing the exchange and sharing of data in the library network, as well as for cooperation among libraries and surrounding systems, especially the publishing sector. We present the advantages of implementing linked data formats for collaboration in libraries and among libraries and surrounding systems in the Web environment. The study is intended to contribute an outline of a solution for the implementation of an ecosystem of linked open data in the Czech Republic.

From MARC to Linked Data

Bibliographic and authority data processing in the Czech Republic is shaped by a number of standards. MARC 21 has been used as the main exchange format since 2004, with the RDA Cataloguing Rules (Original version) being used in combination with the MARC 21 format starting from 2015. These international standards are supplemented by methodologies and interpretations published on the National Library of the Czech Republic’s website devoted to cataloguing policy. However, for over almost two centuries, a number of other standards and methods have been used in our territory. Many collections have historically been processed on cataloguing cards according to various standards. The cards only began to be converted into a machine-readable form in the 1990s onwards as part of retrospective conversion (machine reading of cards) or retrospective cataloguing (with a document in hand) projects. As a result, we can really find a mixture of many different approaches and rules in today's databases.

Since we have adopted MARC 21 as a standard in the Czech Republic in 2004, it might seem that it has been a relatively modern format. However, the opposite is true. MARC 21 closely follows its predecessors, whose creation dates back to the 1960s. Therefore, the format has gone through almost sixty years of history, and as discussed in the On the Record report (Library of Congress. Working Group on the Future of Bibliographic Control, 2008), it was created using relatively old programming and data management techniques, from today's point of view. The MARC 21 format is closely related to Anglo-American cataloguing procedures, its form was influenced by the form of a paper cataloguing card. It is still necessary to use punctuation according to the ISBD standard (International Standard Bibliographic Description) for the data structure in some fields and subfields. The overall structure is very outdated and inflexible. It cannot respond well to the present day’s data models (e.g., IFLA Library Reference Model, hereinafter referred to as IFLA LRM, Riva, 2017). The MARC 21 format is often used in library systems not only as an interchangeable data format. Library systems often offer forms for cataloguing based on individual fields of the MARC format, the fields are marked with appropriate tags, the librarian writes down the indicators, marks the individual subfields, and must use the prescribed punctuation.

MARC 21 (or other MARC formats) is used exclusively by the library community and is essentially incomprehensible to other systems used in memory institutions (archives, museums) or in publishing and book market systems. For the above reasons, as well as for the benefit of better communication of data within the broader environment of libraries on the Internet, and especially for easier communication of data in the Web environment, it would be more appropriate to abandon the MARC formats and start using formats based on more general standards also used outside library sector.

Libraries around the world have worked with MARC formats and related technologies (e.g., Z39.50) for a really long time, using them to share hundreds of millions of bibliographic and authority records. "Everything from system integration to all cataloguing work is built on the MARC 21 format," as the National Library of Sweden’s experts state (2019). It is therefore very difficult to put an end to such practice and start using completely new procedures and techniques. In order to evaluate the possibilities of converting existing bibliographic and authority data into linked data formats, it is necessary to examine in more detail the processes of creating bibliographic and authority records in the Czech Republic and especially the cooperation in their creation.

First of all, we will explain in more detail how to work with linked data in libraries abroad and what impact the implementation of linked data formats could have on the entire data processing process in libraries.

The Topic of Linked Data in Libraries

The use of linked data in library systems is not a new topic in the Czech Republic. Already in 2010, Jindřich Mynarz and Jan Zemánek (Mynarz and Zemánek, 2010) published a paper titled Introduction to Linked Data in the Knihovna plus, where they characterize the principles of linked data formats and their (as they themselves state) technological profile. A large part of the paper is devoted to the use of linked data in the library sector, as an example from the Czech Republic, they mention the conversion of the Polythematic Structured Entry Index to the SKOS format (National Technical Library, 2016–2024).

In the following years, papers in Czech mentioning these topics would follow, by Barbora Drobíková (2013, 2014), Klára Rösslerová (2016, 2017a, 2017b, 2018), and Helena Kučerová (2018, 2019). An important achievement in this area are the projects of the National Library of the Czech Republic related to the interconnection of the TDKIV terminology database and the name authority database with Wikidata, which are described mainly in the works of Linda Jansová (2019, 2020) and Zdeněk Bartl (2019). The possibilities of using linked data in the Knihovny.cz database are described by Michal Denár and Josef Moravec (2023).

For more information about linked data in libraries, you can use the links page on the Information for Libraries portal (National Library of the Czech Republic, 2024). In 2023, the Cataloguing and Linked Data webinar was organised by the Union of Librarians and Information Workers of the Czech Republic (SKIP ČR). Videos from the webinar are available on the SKIP ČR website.

A large number of papers have been published and written on the topic of linked data in libraries abroad in the last twenty years. A systematic review of published resources on the topic of linked data in libraries was presented by a team led by Panorea Gaitanou in the Journal of Information Science (Gaitanou, 2024). The paper summarizes works published between 2008 and 2019. It deals exclusively with articles published in expert periodicals written in English, book chapters, and papers in proceedings. It does not include any theses or dissertations, white papers, or similar sources.

The results of the systematic review are divided into several chapters:

- Linked Data Implementation in the Cultural Heritage Domain, including subchapters: Linked Data Implementation in Libraries and Bibliographic Control, Linked Data Implementation in Specific Projects, Specific Approaches to Linked Data and Methodologies;

- Description of Specific Bibliographic Models, including subchapters: FRBR , BIBFRAME, and RDA models;

- Interoperability Issues: Mapping and Crosswalks, including subchapter Mapping and Crosswalks Using the BIBFRAME model;

- Other Issues, including subchapters: KOS (Knowledge Organization Systems), Linked Data and Metadata Quality, Privacy in Libraries, Librarian’s Position o in the Linked Data Environment, and Educational Material.

The authors processed a total of 239 sources. The above chapter and subchapter titles clearly show which topics were most often covered by the published sources in the period 2008–2019. These are mainly topics related to bibliographic and authority control, the IFLA LRM and BIBFRAME models, interoperability of metadata in library systems with an emphasis on the transition to new linked data formats. The systematic review confirmed the fact, as the authors themselves state, "that linked data are becoming the mainstream trend in library cataloguing especially in the major libraries around the world as well as the most important research projects initiated by libraries in an attempt to make bibliographic data and collections more discoverable in the WWW and their users, more meaningful as well as more reusable " (Gaitanou, 2024, p. 218). However, thanks to such a detailed overview, it is also clear that there are topics that many authors have not yet touched on in their research work from the period 2008–2019. Gaitanou and colleagues state that these are mainly topics related to metadata quality control, lack of rules for handling (meta)data and sharing (meta)data in RDF format, and other topics.

From more recent works, we would like to mention Sophie Zapounidou's dissertation from 2020 entitled Study of Library Data Models in the Semantic Web Environment, in which she compares FRBR, BIBFRAME, RDA and EDM models . Julie Unterstrasser's 2023 thesis is also very inspiring, showing how the transition to the linked data format has affected the work and practice of librarians at the National Library of Sweden. The author emphasizes the significant shift in the work of cataloguers "from cataloguing to catalinking", or from cataloguing to creating links, as a fundamental change in the paradigm of bibliographic and authoritative processing of information resources in libraries. The aspect of the necessary further education of librarians in the field of linked data is also important.

The importance of the topic of linked data is shown not only by the articles published or dissertations, but also by specific ongoing projects to implement linked data formats into bibliographic control processes in many large libraries around the world. Since 2017, the BIBFRAME Workshop in Europe (https://www.bfwe.eu/) has been held annually to bring updates on the state of linked data formats’ implementation from European countries with a large number of current papers by prominent authors in this field. The studies and conference papers by Ian Bigelow with co-authors from the University of Alberta (e.g., 2020, 2022, 2023), Tiziana Possemato with co-authors from the Casalini Libri Library (e.g., 2020, 2022, 2023), which is the organizer of the workshop, or Stanford University’s Nancy Lorimer (e.g., 2022, 2023) or Library of Congress’s Sally McCallum (e.g. 2022, 2023), and many other experts are inspiring.

The number of projects already implemented for the conversion of bibliographic and authority data into linked open data formats is also shown in the Proposal for the Publication of Linked Open Bibliographic Data, a 2023 study by F. A. de Jesus and F. F. de Castro, who identified a total of 58 projects from around the world, projects of national or university and specialized libraries and networks in Spain, Finland, Sweden, Germany, Hungary, and, especially, the United States of America.

The need to switch to linked data is also shown by the 3R Project, which aimed to completely redesign the RDA rules in the Original version to the RDA in the Official version. The RDA Official includes the RDA Registry as its integral part – ontologies for the RDA/RDF linked data format. The aim was also to completely redesign the RDA Toolkit, individual instructions and paragraphs with regard to the use of rules in combination with linked data formats (e.g. Alemu, 2022, p. 197; Oliver, 2021). It is assumed that from 2026 onwards, RDA will only be used as rules in the Official version, and the Original version will be cancelled.

Entity-Oriented Cataloguing: How Bibliographic and Authority Data Management Can Change

As early as 1995, Michael Heaney published an important study dealing with object-oriented cataloguing (Heaney, 1995). The AACR2R cataloguing rules were the context of his study. Heaney called for greater emphasis on the precise identification of the different types of authority that can be interlinked. Networks of linked authorities would then represent individual records. It can be said that such a visionary work can now be completed in a certain way. In the context of linked data formats, new terms emerge, such as identity or entity management or entity-based cataloguing (e.g., Durocher et al., 2020; Stalberg et al., 2020; MacEwan, 2022; Zapounidou et al., 2024).

Linked data technology is based on precise identification of structured data that represents entity instances and the relationships between them using unique URIs (entity instances, relationships, and their corresponding URIs are registered in controlled dictionaries and ontologies). Structured data representing certain types of entities and controlled dictionaries, as Zapounidou et al. (2024) wrote, are the very heart of the cataloguing process known as authority control. At this point, the authority control processes, as we know them from library databases, coincide with linked data management technologies. However, managing linked data requires highly automated processing based on URIs. We often rely on human interpretation and the use of textual chains in authority control processes, e.g., at the level of the selection of authorized input elements according to various cultural and linguistic conventions (see Zapounidou et al., 2024 for more details).

If we discuss entities, then linked data formats, whether we mean, e.g., BIBFRAME or formats based on RDA/RDF and IFLA LRM, will require management of all entities that occur in bibliographic databases. This concerns not only entities that are in the area of interest of authority control today, such as names (personal, corporate), titles of works, geographical names, or subjects. In the language of the IFLA-LRM model (Riva et al., 2017), there are also entities related to expression, manifestation, item, agent, nomen, or time span. For instances of all entities, it is necessary to manage value vocabularies with unique URIs. Document identification (today represented by a bibliographic record) will then be formed as a network of mutual relationships among entity instances (individual occurrences of entities, e.g., a specific person, a specific place), and both relationships and individual entity instances will be represented by URIs (in reference to J. Unterstrasser (2023) above: "from cataloguing to catalinking".)

Advantages of Linked Data Implementation Not Only for Cataloguing

So far, we have only dealt with the implementation of linked data formats in the field of library data management or cataloguing. However, the advantage of deploying linked data formats is best reflected in the interconnection of library databases and external resources in the Web environment, in better visibility of libraries on the Web, and thus in better services to library users. MARC formats are not easy to understand for other systems outside the library community. Linked data formats can enable better interoperability of data across communities – the publishing environment, the GLAM sector – galleries, libraries, archives, museums. Publishing data in linked data formats will make it easier for web search engines to index data from library databases and make the data visible in normal web searches. Such data will enable the interconnection of library databases with external sources of information, such as GeoNames or Wikidata, and enriching the user interfaces of library catalogues and discovery systems from external sources.

The first outputs of data enrichment projects from external sources can also be tested in the Czech Republic, e.g., in the Knihovny.cz portal, as described by Denár and Moravec (2023). The NKlink tool is another example of a good practice (Jonáčková & Dostál, 2020), which enriches authority records with external identifiers, including Wikidata identifiers. The ability to enrich library data with data from external sources is one of the most common arguments for the deployment of linked data formats in libraries and the replacement of obsolete MARC formats. Because the introduction of linked data will help to work with data much more efficiently, it can offer users new search options that are currently only available in complicated ways or are not available at all.

Situation in the Czech Republic

Cooperative Production of Bibliographic Records

The cooperative production of bibliographic records in the Czech Republic is built on several pillars. The main pillar comprises centrally defined standards, such as cataloguing rules (in the Czech Republic, these now include RDA: Resource Description and Access, Original version) and the exchange format (MARC 21 bibliographic and authority format). Other important pillars comprise building of the Czech National Bibliography (including a set of national authorities) and producing union catalogues, to which Czech libraries can contribute new bibliographic records and from which libraries can download records for use in local databases.

The Czech National Bibliography (CNB)

Under the Act No. 257/2001 Sb. (hereinafter referred to as the Library Act), Section 9(2b), the National Library of the Czech Republic "prepares the national bibliography and ensures the coordination of the national bibliographic system". According to the subsequent sections of the same Act, all regional libraries (Section 11(2a)) and specialized libraries (Section 13(2a)) collaborate on this task.

The basis of the CNB consists of libraries within the so-called "cluster": the National Library of the Czech Republic, the Moravian Library in Brno (also in the role of the regional library of the South Moravian Region), and the Olomouc Research Library (also in the role of the regional library of the Olomouc Region). These libraries work within a shared database. In addition, the records of regional libraries are received by the CNB through the Union Catalogue of the Czech Republic. Bibliographic records for fiction are contributed by the Municipal Library in Prague as part of the Central project (Lichtenbergová, 2023). Development of the CNB is one of the so-called national functions of the National Library of the Czech Republic. The CNB database is a very important and irreplaceable source of information on published cultural heritage in the Czech Republic.

The CNB currently makes 1.2 million records available. The contribution to the creation of the bibliography can be illustrated by the statistics of the originators of records generated according to the new RDA rules in force since 2015. Since that year, 209 thousand records have been created according to the RDA, including:

- 64 thousand records by the National Library of the Czech Republic – location code ABA001

- 19 thousand records by the Moravian Library in Brno – location code BOA001

- 18 thousand records by the Olomouc Research Library – location code OLA001

Together, these three libraries have created about a half of the bibliographic records at the CNB since 2015. Other regional and other specialized libraries participated in creating another hundred thousand records, and several records were even originate from a foreign library. The Municipal Library in Prague contributed with almost 13 thousand records16.

Union Databases

The Union Catalogue of the Czech Republic, a centralized heterogeneous union catalogue, contains 8.4 million bibliographic records, including the CNB records. It has been available electronically since 1995 (Svobodová, 2003). Currently, 530 libraries collaborate on its development (Union Catalogue of the Czech Republic, 2023). According to the Act No. 257/2001 Sb., Section 9 (2a)), the Union Catalogue of the Czech Republic is produced by the National Library of the Czech Republic. In addition to the CNB, the building of the Union Catalogue is also part of the so-called national functions of the National Library of the Czech Republic.

Only monograph records can be contributed to the Union Catalogue via the OAI-PMH protocol. For serial resources, it is possible to update subscriptions of individual titles using an online form. The frequency of contributions varies. When data is entered into the Union Catalogue, multiplicity and quality of records are checked. In the event that an entry already exists in the Union Catalogue of the Czech Republic (hereinafter referred to as the SKC), only the location code of the new (sending) library is registered and a link is created to its local catalogue. For a new record, the entire record is inserted into the SKC, including the link to a local base. Where a record does not have the desired quality, it is returned to the sending library for correction. Some libraries do not provide their entire collections for harvesting in the SKC database, but only a certain selected part, e.g., by document type.

We should mention the Knihovny.cz portal as another representative example of union databases, which now includes 100 libraries. In addition, the portal provides access to other resources that it harvests, including the Union Catalogue of the Czech Republic (Knihovny.cz, 2024b). Using the Z39.50 protocol, libraries can have their individual profiles defined, which allow them to search and download records from various Czech and foreign sources (Knihovny.cz, 2024a). The advantage of the Knihovny.cz database is that it often receives records of a larger part of the collections from libraries. It is therefore a relatively interesting source of, for example, audiobook recordings or special documents such as talking books or board games.

Given the role of the Knihovny.cz portal, the titles here do not have a truly collective record (SKC). For the purposes of searching, the system works with each record that it has received from all libraries that hold the title. The records are interconnected using duplicate control (Kurfürstová et al., 2023). A different record is used at different times, for example, based on a home library of a logged-in user, or the selection of a library when searching. All records in the Knihovny.cz index are then offered through Z39.50. Their quality varies considerably. At the same time, however, the portal often provides records that are not available in other sources.

Current Collaboration Workflow

In addition to the indisputable advantages that result from the development of the CNB and union databases for cooperative cataloguing, it is also possible to observe certain weaknesses that have accompanied the existing models of cooperation throughout the existence of library databases, and not only in the electronic environment. We could summarize them using two concepts of multiplicity and asynchronicity. This is reflected in practice, for example, in the following situation: a library requests a complete record of a title that has just been delivered, for example in the Union Catalogue of the Czech Republic. If the library does not find it there, then it will have to create such a record. This can happen in the span of hours or days in a number of libraries. If a library cooperates with the SKC, the record created by it will be harvested via the OAI-PMH protocol, sometimes with a weekly (or even monthly) periodicity. In the SKC, multiplicate records of various quality are created, which must be deduplicated in a complex way. Moreover, it is not easy to apply partial changes to deduplicated records based on records sent from libraries. At a certain point, the system only registers that the title exists in the given library.

Thus, part of the work generated by this parallel activity is not relevant to the cooperative system. In individual libraries, records of varying processing complexity and quality are created in such manner. This does not mean that the system is poorly designed. All negative properties are based on the multi-speed dynamics of the distribution of records in the system. This is partly due to the fact that harvesting records from hundreds of libraries is time-consuming, as is the subsequent deduplication and further processing on the part of the union databases. The MARC format also plays a role, as its structure often does not allow for effective qualitative evaluation of individual records with regard to the creation of a high-quality union record. Algorithm-based evaluation weighs are used, but these tend to work with formal record checks. This is also due to the fact that the amount of information in the MARC structure is recorded only as text, without placing it in a broader context or assigning a specific meaning to the information. The whole process is made even more complex by the complicated syntax and rules for creating records, which in some respects allow different approaches to description or notation.

As mentioned above, the CNB is produced mainly by the three major libraries in the cluster. These libraries obtain published documents in the Czech Republic mainly in the form of legal deposits. This in itself often brings significant delays in the processing of documents that have been available on the market for some time. In reality, regional or specialized libraries are able to obtain these documents earlier than the "cluster" libraries, and are forced to be the first to process the documents. Given the requirements of their users, they often cannot wait for a high-quality record to be created at the CNB or for the record to be downloaded into the union databases. Although the CNB forms the basis for the SKC, especially in the area of Czech production, it may happen that the records in the CNB differ from the records of the same titles. They contain some practical information that will be appreciated by both lending service workers and readers. An example can be an indication of pertinence to a cycle or high-quality annotation.

The biggest problem of the current cooperative system is the considerable number of duplicates and multiplicity of records. These are created by the fact that records from local databases are received in central union databases at different times. This is mainly due to the acquisition policy of individual libraries in connection with distribution. In addition, libraries send their records to union databases at various frequencies. As regards fiction, the Central project managed by the Municipal Library in Prague (Projekt Central, 2024b), has significantly helped with the speed of cataloguing new titles. The project purchases fiction 3 times a week and process around 16 titles a day. They state that they send new publication records to the Union Catalogue 3 to 7 days of publication. However, asynchronicity occurs here as well. According to statistics, the project will cover approximately 80% of fiction published in our territory by the largest Czech publishing houses (Projekt Central, 2024a).

Design/Outline of a Vision for Future Solutions

In the cooperation model, where the recording is created only after the document is published and placed on the market, these weaknesses cannot be avoided. This situation could be addressed in many cases by creating a record before the document is issued or, at the latest, in parallel with its launch.

An important player could be the newly built joint database of libraries and publishers called the Register of Czech Books, sometimes also called ReČeK for short (Maixnerová, 2023). Thanks to it, libraries could obtain basic metadata before the title is released. The project could offer a usable data alternative to "cataloguing in a book", which has only partially spread in our environment, rather in professional literature. Thanks to the direct recording of values by the publisher, the record could be more complete than the CIP and ISN (reported books) databases currently provide. In addition, metadata will be available for download before the publication of the book in the library network (e.g. for acquisition purposes), starting with the creation of a record and in one place. The persistent entity identifier will remain the same and public, but the metadata will be further added during the cataloguing process. Until the title is actually published, the data can be edited to react, for example, to changes in the title or the number of pages.

If each such title also received a unique identifier (before the ISBN and the CNB), it would be possible to create records referring to this identifier. If a central metadata repository is also created in the National Library, it would be technically feasible to distribute all changes in records to the entire ecosystem. This would create a single record that would be distributed by the system to local databases. This solution could prevent the creation of different versions of records between the central database and the local record in the connected library. At the same time, the central record could be complemented and improved in a cooperative way. Any change would soon be reflected in all local copies. In addition, it would be possible to insert certain data only for local use, or, conversely, to hide some information for use in a specific library.

National Authority Files

Today, we can no longer imagine high-quality bibliographic records without access point based on authority files. Authority files are an important building block of bibliographic databases, allowing to uniquely identify specific instances of entities, link bibliographic records, and playing a significant role in searching databases and metadata. At present, library databases mainly use authority records for persons (personal names), corporations, subject terms/descriptors, formal descriptors, geographical names, titles of works and expressions (in the form of authority records for anonymous works, or in the authority records of the name-title type for works listed under the author's name). However, the representation of the authoritative forms of the above-mentioned types of entities is far from being one hundred percent in bibliographic records.

As an example, the CNB database contains 866 thousand records with the field 100 (Main entry – personal name). There are 797 thousand occurrences of the subfield 7 that contains an authority record’s identifier. Of the 731 thousand occurrences of the 700 field (Added entry – personal name), the subfield 7 with an authority record identifier has 628 thousand occurrences.

The CNB database can be considered a very well-managed database with the best quality of cataloguing possible. Personal names are the most common and most commonly produced authority records in general. Nevertheless, even in the CNB’s fields 100 or 700 for personal names, not all forms of names are based on authority files. Such a situation is quite logical, because the CNB contains different layers of records from different periods.

Table 1 Proportion of identifiers completed for CNB personal and corporate authority records

In addition to the data that can currently be linked to authority records, there is also data in bibliographic records for which it would be appropriate to create authority records or controlled vocabularies for the sake of unambiguity of search and linking, but this is not done as a result of the cataloguing traditions. These concerns mainly data on publishers (the issue was addressed, for example, by Drobíková et al., 2016), places of publication or production of documents. We can also include the issues of recording time/date or time span (the time span occurs in many fields of bibliographic and authority records – e.g., date of publication, field 264, 008; date of record creation, field 008/00-06, date of record update, 005, dates related to the document’s content given in the subject fields – 648, 045, for authority records, these concerns data associated with individuals, corporations, with the time-limited existence of administrative units, or with the creation or updating of a work, or its expression, the creation of a recording, etc.).

Collaboration on Authority Records

In the case of authority records, cooperative creation in the Czech Republic is used mainly for authority records of personal, corporate and geographical names. The cooperative creation of other types of authority records (subject terms, title authority records) is limited to the cooperation among the relevant departments of the National Library of the Czech Republic and cluster libraries due to the more demanding administration, complexity of the structure, and dependence on the terminological systems of individual subject areas. In practice, therefore, we often encounter situations, in which libraries use non-authoritative forms of names and titles in the relevant fields (title, subject). The possibility of linking such records may be significantly limited for these reasons.

Like in the case of collaborative production of bibliographic records, there is a delay and a certain asynchronicity in the creation of authoritative records, too. Authority records for authors are usually created only after the publication of a document, generally a printed one, especially a book. To a lesser extent, article production is taken into account, and authors of articles in Czech periodicals or periodicals published in our territory are taken into account. The scientific community publishing articles abroad or the authority files for their research workplaces often do not even fall within the scope of Czech national authority files. A similar situation is common for other types of documents, such as electronic textbooks or educational videos.

Authors (and other originators) of works that are published only electronically now also remain unprocessed. Where an electronic legal deposit is received, there will be a need to create authority records even for authors who have not yet been processed. This may mean an additional burden for the National Library of the Czech Republic. In the future, the solution is to decentralize the production of authority files as much as possible among a larger number of cooperating entities that will form a single metadata base together. This system should be designed in such a manner as to allow for different levels of rights for registration and suggesting modifications. The solution must be set up so that despite the participation of a broader community, duplicate records are still minimized . The complete elimination of duplicates is unlikely to be avoided in the future, but efforts will continue to minimize their occurrence, both at the process level and through the use of technical tools and procedures.

Independently of authority record production, a unique identification of authors is being expanded using other types of identifiers around the world and in the Czech Republic, e.g., ORCID identifiers (Open Researcher and Contributor ID) for publishing in the field of science and research or the ISNI identifier (International Standard Name Identifier) . Experts from universities and research institutions may apply for the ORCID identifier before a publishing activity takes place. The identifier assigned then accompanies them in the publication of various sources (e.g., studies, textbooks, articles in electronic form), whether in the Czech Republic or abroad.

Linked Data as a Means for More Efficient Library Collaboration As we mentioned earlier, the MARC format now affects the entire process of producing and distributing metadata. Using a timeline of the process of creating one particular record in the Union Catalogue of the Czech Republic (SKC), we can demonstrate how the current model works.

We chose the work Šikmý kostel (The Leaning Church), Part Three, by Karin Lednická, as a sample record. The title was published on 15/04/2024 and its record appeared in the SKC on the next day, on 16/04/2024. Unfortunately, it contained an incorrect CNB number (field 015). Since it was a planned and anticipated title, the interest in the record from libraries was considerable. The record began to spread across libraries via the Z39.50 protocol, including the error. There is no way to count the number of downloads. Only some of the libraries that used the record are involved in the cooperative cataloguing for the SKC. This means we can only monitor the number of imports from individual libraries. Individual imports can be related to specific days and times, but these are often not the same as the date of entry into local databases.

As we mentioned above, imports to the SKC usually take place in weekly cycles, but in practice we encounter both shorter and significantly longer intervals. The error was corrected on 24/04/2024 by an SKC employee. Automatic editing of records in local databases after a change in SKC is an issue, and thus records are usually updated manually, or not updated at all. Some errors may remain in the library databases. In a sample of records, we found some records not containing any CNB numbers at all. This may be a problem in the future, as it is a key identifier that can play an important role in future migration to linked data formats, as well as help in further work with metadata. Without the identifier, unique identification is difficult to imagine .

Fig. 1 Šikmý kostel (The Leaning Church), Part Three (2024): a timeline of record changes

The transition to linked data should also include a set of strategic decisions that will help us tackle most of the problems brought about by the existing system of cooperation during the change. We should focus on two key aspects that we have identified, i. e., time asynchronicity between the need for a record and its delivery to the central repository, and the absence of a unique title identifier that is available before release. Another key feature of the new solution is an ability to distribute all changes from the repository to the participating institutions very quickly, almost in real time.

The Register of Czech Books (ReČeK) should be given an essential position in the planned system. This database should be co-created as a joint work of publishers, libraries, and the Czech National Agency for ISBN and ISMN. It will contain information about books from the moment they are included in the publishers' editorial plans. Publishers require an ability of ReČeK to provide structured information on titles in the ONIX format , which they set as a pre-condition for their cooperation. The ONIX format is successfully used internationally for the needs of publishers, distributors, and booksellers. ReČeK should then enrich information from publishers with contextual information that is important for use in libraries (linking authors to personal authority records, subject authority entries mapped to publisher's subject description, publishers' databases, etc.). The plan is that an ISBN will be assigned immediately when a record is imported to ReČeK. The system must then be able to provide the "library version" of the metadata to libraries, at least for a transitional period, in the MARC format, and, at the same time, in a structure suitable for linked data creation.

When creating a record in the ReČeK database, a record should ideally be created at the same time in the central metadata repository (with feedback to the ReČeK system). The linked data structure will allow for a better description of the interrelationships among entities. It will be necessary to rethink the ways in which certain kinds of records are created.

According to the instructions currently in place, it is possible to create either a collective record for all volumes (top-down), or records of individual parts (bottom-up) for multi-volume monographs. The instructions define some cases for choosing either of the options. Unfortunately, due to varying interpretations of the instructions, it happens that different libraries create records for the same titles using both top-down and bottom-up approaches. It is not always easy to distinguish such records from each other at first glance. Their structure can be very similar. Especially, when searching via Z39.50, it is not clearly stated anywhere in the interface whether a record concerns a single title or a series of titles. It is possible to distinguish such cases only with the help of some (basically partial) aspects of the record – for example, the year of publication can be written as a range for a series, the physical description will contain the number of volumes instead of the number of pages, and so on, for group records the code "a" should be given at position 19 in the LDR . Sometimes it happens that a collective record with the CNB number is downloaded to a local database, which is then modified using the bottom-up approach and the CNB is not removed, which then causes complications in the identification of the document.

In the linked data structure, we have significantly more options for connecting individual entities into logical units, including hierarchical links. We can easily distinguish such entities by having different classes. Links can change dynamically over time. For a better understanding, we give a specific example, again using the title Šikmý kostel (The Leaning Church).

In the CNB database, there is a so-called collective record for the Šikmý kostel (The Leaning Church) series, and the record has been assigned its own CNB identifier. The record also contains the ISBNs of the individual parts. At the same time, there may be separate records for the individual volumes in the Union Catalogue of the Czech Republic and in local library catalogues. In a description using linked data, we can link the records of individual parts to each other.

Similarly, for example, in the case of personal authority records, different identities of persons can be combined. Again, there is no need to create an umbrella record that contains various reference forms of names, pseudonyms or language variants of names. Everything can be defined by mutual relationships of entities. However, a collective entity may also exist, depending on the ontology used/designed.

When designing formats and links, we should not remain limited by the established approaches to description, which have been influenced by the UNIMARC format over the decades, later by MARC 21 and the cataloguing rules used. Rather than that, we should start from more general principles in order to create structures that allow us to describe reality in a straightforward manner. Linked data records can gradually grow and gain in complexity. In the beginning, there may be a simple vertical structure, which may form complex tree structures as the number of volumes increases. However, linked data, unlike the MARC format, will allow us to look at these structures from many angles and directions, depending on what interests us. Metadata can be produced in a decentralized way, but the results will be available in one place.

Decentralization of metadata production will allow the involvement of different players, and specialization in a certain area will then play an important role. Part of the work will be done automatically by bots specialized in specific tasks. For example, bots in the Wikidata project add identifiers to existing items from external sources, or add links to each other.

Prerequisites for Transition to Linked Data

The RDF data model, as the cornerstone for linked data technologz, distinguishes (in addition to an empty node) two basic types of nodes that can occur in data triplets at an item’s location – URI (or IRI) and the so-called literals. Our goal should be to make the most of URIs referencing an item. This leads us to obtain as much information as possible from authority files, ontologies, thesauri, and controlled vocabularies. Therefore, we need to have these building blocks ready before we start producing records as linked data. The first decision is the selection of suitable sources that will be the basis of future metadata.

Authority files are one of the important sources. We cannot do anything without name and subject authority records, converted into linked data formats. We should also map suitable sources at the national level, but we must not forget about sources from other countries. For example, we do not have an up-to-date controlled vocabulary with data on publishers at the moment. This could be provided by the ReČeK in the future. The next step will be to prepare the suitable sources for use in practice. This will involve conversions to the necessary formats and structures. The resulting ontology map should be constantly maintained by a curatorial team, which should search for new sources and oversee the relevance of existing sources.

Work in other types of record editors is also a prerequisite . The creation of linked metadata will be significantly different than in the current cataloguing editors that we commonly use for MARC (a cataloguer will perform "linking" rather than "cataloguing"). Some fields will be linked to large value lists, and an editor will have to work well as a guide. Loading values should not slow down the work significantly.

Table - SWOT analysis

Where are We Heading?

The transition to linked data is not merely replacing one metadata type with another. Linked data brings a very different approach to recording reality using metadata. If we embrace this change, then new possibilities will open up for libraries, especially in the area of cooperative metadata production. This should not make us complacent; we must also strive to ensure that the newly designed system provides tools that will allow us to better manage the quality of metadata and make the process of its production more transparent.

Abandoning the MARC format, which is understandable only to libraries, provides us with a unique opportunity to open up data even more for further use outside of our ecosystem. It is not enough to just expose packages of data under a suitable open licence. We also need to offer the right tools to work efficiently with millions of records. Such tools include APIs (Application Programming Interfaces), which are a necessary basis for ensuring integration to information systems or applications. For analytical purposes, we should offer a certain form of a query service, which allows us to obtain various types of structured information in the form of queries. Last but not least, we must offer a user-friendly search interface to professionals and the general public.

The transition from the MARC format will be gradual. We have to take into account that for the transitional period of time we will create metadata both in the MARC format and in the linked data structure. If we are to work efficiently, we cannot create all the data in both ways. Probably the best way is to create linked data that contain specific MARC fields. From such hybrid records, it is possible to generate records of a sufficient quality level in the MARC format without redundant duplicated work. This is the path that some libraries are currently taking in other countries. In the design of the future system, that part working with the MARC format should exist as a temporary module that can be safely switched off when it is no longer needed.

When designing the system, we should always be aware of the limitations that exist in the current solution. These include:

- occurrence of multiplicate records in the metadata ecosystem,

- different approaches to describing different types of documents,

- central repository built on proprietary technology that does not allow access from different systems,

- very limited possibilities of distributing changes in records to local databases,

- limited possibilities of logging activities in the repository,

- inability to perform more complex queries on datasets,

- in the event of a failure of the central repository or a distribution service, the necessary data is not available,

- inability to export from the repository in a format other than MARC,

- limited capabilities to perform more complex analytical or statistical queries on the data in the repository.

The figure below shows a schematic design of the system’s individual modules for shared creation and distribution of metadata. So far, it is a more general concept that is based on two requirements: the system will use linked data and functionalities and will try to address the existing limitations and problems of cooperative metadata production, especially on the blueprint of the Union Catalogue of the Czech Republic and its existing services.

The metadata repository is at the heart of the solution. The repository is intended to be centralized, with decentralized distribution of metadata to local databases in the participating libraries. The repository should be independent of the library system that will be used by the National Library of the Czech Republic in the future or that will be used for the administration of the Union Catalogue of the Czech Republic. It should also be possible for library systems and other systems to cooperate with the repository. Records in local databases will be exact copies of a central record, including identifiers. Thanks to the fact that the identifiers are of the URI type and always fall into a specific namespace, the data is compliant – unlike records in the MARC 21 format, where the identifiers are usually valid only locally and the link to the original record may be lost. Any change in the central record will be readily synchronized with local databases.

A local database will also serve as a redundant backup, from which it is possible to restore records in the central repository. Each local repository has the option to attach locally used information to the record, which will not be synchronized with the central record (it will exist in a different namespace). The local system and search interface will make it possible to hide part of the information from the central record that is not used in a particular library, or, on the contrary, to display additional information from external sources according to current needs, or to attach information important only for a specific local library to the local record and it is not distributed to the central repository.

All the building blocks needed to create records will be stored in the repository, including not only instances of entities that we use to identify authors or for subject description, but also values from various lists or vocabularies. These will be obtained by converting existing authority files, but it will also be possible to obtain them from various external sources. However, such sources will first have to be selected, and have their quality and long-term sustainability evaluated.

Robust tools must be available to efficiently manage the data stored in the repository. Since the solution will significantly reduce duplication, it will be possible to focus more on quality. To that end, repository administrators will need tools that allow them to proactively scan for possible errors and fix them quickly. At this level, we should also count on the deployment of automated tasks based on machine learning. Each such task should be trained on the data available in the repository and its functionality verified by experts. Such tasks can help troubleshoot errors in metadata acquisition. They can also enrich or link individual entities to each other.

By linking individual entities as building blocks, successors to today's records will be created to identify documents, their contents, people, but also the actual libraries. Such a solution must be ready to provide both linked data and data in the MARC format for a transitional period, but without the need to create entire records twice. This can be achieved, for example, by temporarily including a portion of specific MARC fields in the linked data format records. This involves some fields that would be complicated to generate from linked data in the required syntax. This is currently quite common in libraries in other countries. In this manner, it is possible to create records in the linked data format and, at the same time, enable the distribution of metadata in the MARC format. Traditional protocols such as OAI–PMH and Z39.50 will continue to be available for distribution. When the moment comes that MARC records are no longer needed, it will be possible to turn off the entire module that handled the MARC distribution.

The solution envisages a close liaison with the planned ReČeK database, which is to be developed with the direct participation of publishers. It is supposed to make it possible for publishers to enter information about titles planned for release. Post-publication data will be available in the ONIX format for book distribution. At the same time, the data will also be used by the ISBN Agency, which will assign ISBNs to individual titles based accordingly. Libraries will also utilize the data. They will have information about upcoming titles, e.g., presale lists, which can significantly benefit the cooperative metadata creation system. Each newly entered title in ReČeK should automatically receive a unique title identifier, through which it will be possible to identify the title throughout the process before and after release. It will be possible to enter a record in the central repository having a relatively high level of quality as soon as the title is officially released. Where a library links it to its local database and later expands or modifies it, the system will overwrite such changes for all libraries where such a record occurs. No changes will take place in a local system.

This should be possible thanks to an editor that will write directly to a central repository. When you try to create a new record, it is first verified that the record for the requested document does not already exist in the repository. If it exists, the creator can extend it or keep it. If the record is not available, the creator will be given the option to create it. Technically, this process must be set up to carefully manage access to the repository and actively prevent duplicate records. A rights system should also be part of the access control for writing. Some users may have higher rights (writing specific "fields", deleting, overwriting values, etc.), others will have limited rights. Rights may be granted by the administrator on the basis of meeting formal conditions, but also on the basis of measuring the quality of record processing.

Users who will create quality records can then obtain higher rights thanks to a good reputation. On the other hand, erring users can lose their rights. The system should also offer the possibility of obtaining and providing feedback. Users should be able to flag errors or inaccuracies. Admin intervention, such as when fixing a bug, could trigger a notification to notify the user that they made a mistake and how it was fixed.

There should also be an API that allows you to pass data from systems other than library ones. It should be possible to add not only various identifiers to existing records or create entire records, but also to add additional information. The API should then ensure that the data is properly mapped between the external system and the repository. The output of the system should be several tools with both public and non-public access regimes. An example of public disclosure would be a search interface that allows anyone to search the records in the repository. We can imagine it as a search in the current Union Catalogue of the Czech Republic or in the database of authorities. API and query services will also be publicly available. Through them, it should be possible to obtain data according to the specific needs of users.

It should be possible to limit the use of public service functionalities in terms of licenses and functionality. In parallel, there will be tools for partners. Their use will also be contractually regulated and their use will be regulated by a contract and the services provided will be tailored to the needs of partners. We can imagine other memory institutions, companies, offices or libraries as partners.

As is already the case, it should be possible to download entire data packages in various formats under the appropriate license and with the appropriate documentation. It should be possible to modify and extend the functionalities of individual modules of the intended solution, as the needs of users grow.

The query service module should be created to allow users to create more complex queries on top of the entire repository. A search can provide significantly more comprehensive search results than a standard search above an index. Such services can be used for various specific types of search, such as domain analysis, science mapping, or book production, based on different aspects.

An important part of the system should be an analytical module. It should provide administrators as well as users with real-time information about the repository. Each user should have data that will make them perceive the repository as a living but transparent organism. First of all, administrators need to know a lot of information about what is happening in the repository, how users behave, and also about how the whole system works.

Since the solution should provide services at the national level, it will be a key system. Its development should be managed by a team at the National Library of the Czech Republic, where all knowledge about its functioning must be concentrated in order to ensure the long-term sustainability of the system, guarantee its maximum functionality and reliability. For economic reasons, the individual modules, or their parts, will be assembled from existing solutions. The actual development would cover the interconnection of individual parts into a functional unit and possibly some partial components. For reasons of sustainability and flexibility, the solution should avoid the use of proprietary products. All development should be made available to the public under an appropriate open license.

Using open development methods will allow more developers to be involved in the process and work to be decentralized. Developers can also change over time without such a change jeopardizing further development. The leadership of the development and its direction must be in the hands of the National Library of the Czech Republic. It can also invite other participating libraries. Such cooperation could be beneficial not only in strategic decisions, but feedback from the libraries involved should contribute to a better-functioning solution as a whole.

Fig. 2 Diagram of the joint cooperative metadata creation system

Discussion

The transition to linked data in libraries is the biggest change in the last three decades. However, it is not just a matter of changing the metadata format. The change means a comprehensive transformation of the entire ecosystem of metadata creation and use. The basic building blocks for linked data have their origins in philosophy and logic. The structure of linked data depends on the ontologies used. Its goal is to describe the real world (SOWA, 1995). This provides a robust foundation for the entire ecosystem of linked data and is a crucial shift away from the single-purpose MARC 21 format.

The ability of individual entities to connect with each other erases the hitherto noticeable boundaries between record types. In fact, the bibliographic record as we know it today will cease to exist. The level of detail displayed by users can vary depending on the requirements of a particular application and the needs of the user. Because we describe real-world entities in linked data, it does not matter whether we describe a book, a person or, for example, an institution (a library). Systems can be created over the linked data that are able to offer searches not only for titles and their authors, but can also link information about libraries, in which the entities searched are available. It is possible to ask a question such as: Find the book "1984" by the author "George Orwell" located in wheelchair-accessible libraries that are open on Saturdays. If we also pay intensive attention to machine processing of full texts in content classification, we can offer search tools that will allow detailed mapping of literature with regard to time, form, places, or topics. The biggest change compared to using MARC is not in how much information describes an object in a record, but how this information is written and how it can be used further. The MARC structure as such makes it possible to make good use of the individual information written in it, but it is not possible to link this information to one another. And if it is possible, such links are often stored in local systems and do not spread throughout the ecosystem. In each of local systems, such links must then be re-established.

In order to be well prepared for the transition to the linked data ecosystem, it is important to open a discussion about the issues of how to describe and identify entities (entity instances) and whether we could optimize some aspects in this area today, even though we are still working with the original formats in the established cataloguing practice. The topics we encountered in our analyses for the purposes of this study relate mainly to the following areas:

• the method of processing multi-volume monographs; the so-called top-down and bottom-up description;
• distinguishing between reprints and editions of individual titles;
• identification of serial publications;
• method of processing authority files vs. identity management.

The list is far from exhaustive. However, the problems identified in these areas are quite significant and already complicate the communication of records both within the library network and the communication of data between libraries and surrounding systems.

Conclusion

The path to linked data will be challenging. It will require a change in the approach and the way of thinking that has influenced librarians and library systems for several generations. In other countries, this issue has been dealt with for several years. On the other hand, there is a certain delay in our settings. However, the advantage may be the opportunity to use the existing knowledge and learn from mistakes that are logically avoided by pioneers.

Valuable information is available from colleagues in other countries on how to go through the whole process in terms of personnel management in libraries. It will be necessary to explain at all levels why we need the change, what it will bring, and what it will require from each of those involved. A crucial step will be to start an early supporting process of retraining the personnel who create metadata. For example, the experience from Sweden speaks of a key role of lifelong learning as a fundamental pillar for a successful transition to linked data.

It is very important that the topics of linked data become gradually embraced by expert discourse in libraries so that the library community gains a broader awareness of the issue and can prepare well for this change. We believe that the present paper has contributed by suggesting a procedure for cooperative metadata creation, which solves most of the weaknesses that the existing shared cataloguing system suffers from, with the help of linked data. This proposal is based on a careful examination of limitations and shortcomings. We are aware that the proposal is still general and cannot give answers to all questions. It was created to open a discussion and to make it possible to further focus on individual parts of the system, as well as to gradually refine its future form. Nevertheless, we think that change is feasible in our environment.

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