Building the National Infrastructure for Digital Heritage Together

Many heritage organizations would like to work NDE-compatible, but in practice run into lack of time, technical complexity and fragmented systems. The guidelines are clear, but implementation requires expertise and continuity.

Polder Knowledge provides just that specialized guidance and technical implementation needed to get beyond the basics. We help organizations move from intention to realization: from strategy and design to implementation, links, public services and sustainable technical solutions.

NDE-Compatible approach for Heritage

Since 2015, the Netherlands has been working step by step toward a national infrastructure for digital heritage. That course is set out in the National Digital Heritage Strategy and put into practice by the Digital Heritage Network (NDE). The goal is to digitally connect fragmented heritage, from small historical societies to national institutions, so that users can easily search, discover and reflect on past, present and future across collections and organizations.

The national infrastructure does not consist of one system or one portal, but a coherent set of:

Working NDE-compatible means that your organization publishes digital heritage in such a way that it can participate optimally in this national infrastructure. Polder Knowledge helps heritage institutions make this course concrete in policy, systems and digital public services.

What is NDE-Compatible Work?

Why is this relevant to your heritage organization? Because working NDE-compatible ensures that your digital collection information becomes findable, connected and sustainably reusable, right at the source.

At its core, NDE-compatible working revolves around one central question: how do you ensure that your heritage information can be easily found, connected and reused, without intermediate layers or dependence on separate platforms?

Numerous organizations preserve pieces of our common heritage: local historical societies, archives, museums, libraries, thematic platforms and national institutions. All these collections are valuable, but often fragmented. The digital domain offers an opportunity to bring these fragments together, provided everyone works according to the same agreements.

The Digital Heritage Network was created for exactly this purpose: to provide national agreements, standards and facilities with which heritage institutions can publish their heritage information in a future-proof and interconnected manner.

Use of standards and architectures

Working according to the principles of the National Digital Heritage Strategy and the
DERA so that everyone speaks the same language.

Linked data in registration systems

Collection or record systems that support linked data, making data machine-readable and linkable.

Sustainable identifiers (PIDs).

Objects, people and concepts are given stable, meaningful URIs so that they can be permanently referenced.

Connecting terms through the Term Network

Link collection information to standardized terms from sources such as AAT, NTA, RKDartists and accessed through the Term Network.

Making datasets findable through the Dataset Registry

Publish and register descriptions of datasets, such as catalogs, collections and inventories, in the
Datasetregister, the table of contents of digital heritage in the Netherlands.

Image unlocking with IIIF

Use of IIIF for sustainable, flexible retrieval and presentation of imagery.

Making information on web pages readable by search engines

With schema.org and JSON-LD, collection information becomes machine-readable. This approach is also known as SEO 2.0 for heritage.

Together, these building blocks ensure that heritage is not only digitally present, but can be structurally linked to other collections and knowledge sources - in the Netherlands and abroad.

The key lies with source holders

The core of the national approach is clear: if source holders have their affairs in order, the rest of the network becomes stronger. Source holders are the organizations that manage collections, from large to small and from national to local. According to the NDE, these parties contribute to the national infrastructure for digital heritage:

1. Source holders (heritage institutions).

  • Using agreed-upon standards and linked data in registration systems;
  • link collections with standardized terms through the Term Network;
  • make datasets discoverable through the Dataset Registry.

    2. Registration system providers.

    • implementing linked data into their systems;
    • encourage use of terms and the Term Network;
    • support export and registration in the Dataset Registry.

    3. Service platforms (websites, thematic portals and apps).

    • Use the Dataset Registry to find relevant datasets;
    • leverage linked data for a richer user experience;
    • Provide cross collection accesses for end users.

    4. Governments and funds

    • base policy and funding on the National Digital Heritage Strategy and the DERA;
    • encourage heritage institutions and vendors to use the national infrastructure.

    Polder Knowledge helps heritage organizations work NDE-compatible, from strategy to implementation of Linked Open Data, Term Network, Dataset Registry, PIDs and sustainable digital public services.

    From fragmented heritage to connected knowledge

    Without agreements, heritage information remains fragmented: each repository its own system, each website its own search function. The national infrastructure for digital heritage breaks through this by creating Linked Open Data at the source and connecting it with standardized terms. This creates a network of information instead of separate islands.

    In this, the Dataset Register forms the national table of contents of digital heritage. By publishing collection data as structured data, for example with schema.org and JSON-LD, datasets become more findable, reusable and usable for thematic platforms, digital services and research.

    The next step: smart accesses via a national knowledge graph

    In the coming years, NDE will add a new layer to this: smart accesses based on a national knowledge graph. By automatically recognizing relationships, patterns and summaries in all available datasets, apps and services will soon be able to answer questions such as:

    • In what sources can I find paintings by Van Gogh?
    • What datasets contain information about World War II?
    • Where can I find publications about Gelderland?

    The better heritage information is connected at the source with terms, PIDs, structured data and Linked Open Data, the more powerful this future knowledge base will become. So working NDE-compatible means: preparing now for this next phase of connected heritage.

    How Polder Knowledge helps heritage institutions become NDE compliant

    Polder Knowledge combines technical expertise with knowledge of heritage processes and NDE guidelines. We connect to tools such as the Rail Book, the Information Planner and the DERA, and translate them into concrete steps for your organization.

    Step 1 - Goals and information plan

    We start by asking why your organization wants to digitize and work NDE-compatible. Consider:

    • increase public outreach;
    • depot and context material visible;
    • facilitate research;
    • enable reuse by creators;
    • strengthen sustainable preservation and internal efficiency.

    With the Information Planner and the Rail Roadmap, we make these goals concrete and administratively explainable.

    Step 2 - Digital sustainability and information objects

    We analyze how digital files and their metadata are organized. We look at:

    • file formats and shelf life;
    • quality and completeness of metadata;
    • rights and accessibility;
    • integral management of the information object (file plus representation information).

    Step 3 - Collection information system (selection or optimization)

    The collection information system is the engine under your digital heritage. We help with:

    • Preparation of a Program of Requirements;
    • The selection or evaluation of systems for collection registration, management or administration;
    • setup based on Requirements for Collection Management Systems;
    • links for export to LOD, Term Network, IIIF and Dataset Registry.

    Step 4 - Linked Open Data, PIDs and Term Network

    This is where heritage really gets connected. We:

    • Help create and implement a PID strategy;
    • link collection information to terms from the Term Network;
    • set up schema.org and JSON-LD on web pages or directly from collection management;
    • Support RDF dumps and SPARQL as needed;
    • arrange or supervise registration in the Dataset Registry;
    • deploy IIIF for imagery.

    Step 5 - Public services and service platforms.

    Once the foundation is in place, we help make heritage visible in public services. We work according to the Architecture Blueprint for Service Platforms and translate the roles of source holders, service providers and developers into a concrete digital application, such as a website, theme platform or app.

    Practice: Polder Knowledge in the heritage sector

    District Collection Foundation - NDE-proof collection management based on schema.org

    For Stichting Wijkcollectie, Polder Knowledge developed a collection management system that allows the organization to be fully NDE-proof. Features:

    • collection data are published as Linked Open Data via schema.org and JSON-LD;
    • Use of standardized terms and durable identifiers;
    • layout aligned with future linkage to urban and rural heritage platforms;
    • the collection connects to the national infrastructure without complex technical management.

    LifeWatch ERIC - Thesaurus for biodiversity.

    For LifeWatch ERIC, we implemented a comprehensive biodiversity thesaurus for plants. Its content is consistent with the principle of the Network of Terms:

    • Standardized names and terms for species;
    • semantic relationships between terms;
    • opportunities to better search and compare datasets;
    • a foundation for offering biodiversity data as Linked Data.

    Frequently asked questions about NDE compatible working

    Do we need to be completely NDE-proof right away?

    No. Becoming NDE-compatible is a journey, not a button. You can start small, such as using schema.org on collection pages or using Term Network terms, and grow from there.

    Do we need a new collection information system?

    Not always. Sometimes optimization of the existing system is sufficient. However, it is important that the system supports Linked Data and links to Term Network and Dataset Registry.

    Isn't Linked Open Data too technical for our organization?

    The technology is complex, but the implementation doesn't have to be. With the guidance of Polder Knowledge and tools such as schema.org, JSON-LD and the Trackbook, any heritage organization can take the first steps.

    Do you have a good real-world example?

    The NDE context often refers to the example of the Verkaufsbücher: registers of expropriated and resold Jewish homes during World War II. By linking this data to land registry data, exact locations could be identified and a new layer of insight was created. The journalistic platform Pointer researched this and discovered, among other things, that real estate traders and others profited from trading Jewish homes. This shows how powerful connected data can be in interpreting history.

    In this example, relationships and sources are still largely linked manually. With a mature national infrastructure - with Linked Data at the source, Term Network, Dataset Registry and a knowledge graph - many of these connections could be made automatically or semi-automatically.

    Ready to connect your heritage to the national infrastructure?

    Do you want your collection to be more than a loose website or local system? Do you want to participate in the network of connected heritage, allowing users across organizations to make new connections? Polder Knowledge helps you get NDE-compatible - from strategic exploration to technical implementation and public services. Contact us for a free consultation and find out what's possible.