> For the complete documentation index, see [llms.txt](https://template.ishare.eu/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://template.ishare.eu/technical-building-blocks/data-interoperability/data-models.md).

# Data Models

According to the DSSC, data models make sure participants in a data space interpret data the same way. Without them, two systems might exchange information but come to different conclusions, which would undermine trust and create errors. DSSC 3.0 recommends first reusing existing data models where possible, extending them where needed, and only creating new models when necessary.

* A data model works like a shared dictionary: it explains what each element means and how it relates to others.
* Agreeing on a reusable model enables semantic interoperability, so providers and consumers “speak the same language” using common standards.
* Different organisations have different needs, so data spaces must balance uniformity (to keep things clear and consistent) with flexibility (to fit diverse contexts).

<figure><img src="/files/13jAxSrhExzM4l9WJRLm" alt=""><figcaption><p>Figure 16. Conceptual Model of the Data Models Building Block.</p></figcaption></figure>

To support this in practice, DSSC 3.0 highlights the use of a vocabulary service for publishing, maintaining, and discovering data models. Datasets and services can then reference the model they follow using standard approaches such as DCAT-AP and `dcterms:conformsTo`, improving discoverability and semantic interoperability across data spaces.

{% hint style="info" %}
See the complete DSSC description [here](https://blueprint.dssc.eu/?pane=technical\&technical=data-models).&#x20;
{% endhint %}

The iSHARE Trust Framework does not prescribe specific models. Instead, data spaces are encouraged to:

* Reuse established standards where possible (sectoral or cross-domain).
* Define lightweight governance rules for creating, updating, and adopting models.
* Focus on lowering barriers so new participants can onboard easily.
* Follow standard data sharing guidelines (like OpenID, etc.) while catering to industry-specific requirements.

Well-managed data models help reduce costs, improve interoperability, and make it easier to link datasets across domains.&#x20;

{% hint style="info" %}
Data Model connects closely with other building blocks:

* **Data Exchange:** Defines how data is structured and transferred.
* **Data Exchange & Data Sovereignty and Trust Pillar:** Uses protocols to ensure secure and reliable data transfer.
* **Data, Services and Offerings Description:** Describes data and services using standard models like DCAT.
  {% endhint %}

{% hint style="warning" %}
The guiding questions can help in the co-creation process and in defining this building block, so please see the next section.&#x20;
{% endhint %}


---

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