Frequently Asked Questions

Semantic resources or shared models are formal and standardized representations of concepts, terminologies, data structures, and relationships used to describe and organize information in a coherent and interoperable manner.
These models, such as ontologies, controlled vocabularies and data schemas, make it possible to share and reuse knowledge between different systems, entities and applications, facilitating the exchange of data and improving the integration of information into the semantic domain.
In practice, they are tools that help make data understandable and usable by different platforms and users, ensuring consistency, precision and interoperability in digital communications.

Schema is the national catalogue for semantic interoperability, an initiative of the Italian Government that collects a set of standardised and shared semantic resources, available to public administrations and individuals.

Promoted by the Department for Digital Transformation of the Presidency of the Council of Ministers, the project is carried out in collaboration with the National Institute of Statistics (ISTAT), which deals with its implementation, management and maintenance, as part of the National Recovery and Resilience Plan (PNRR). The Institute of Cognitive Sciences and Technologies of the National Research Council and AGID are also actively involved, while domain-expert contributors are responsible for the published content. This catalogue represents a fundamental step towards greater interoperability and efficiency in digital public services in Italy.

In the catalogue you will find:

• Controlled vocabularies: Lists of terms, taxonomies, and hoards used to organize terms of reference for different application domains.
• Ontologies: Formal and shared representations by entities and their relationships for application domains of interest.
• Data schemes: Descriptions of data exchanged between different systems, used to define their serialization and validate their syntax.

The purpose of the catalogue is to contribute to and facilitate interoperability between databases of different entities through the design and implementation of a shared semantics that supports the definition of digital services. In particular, the catalog facilitates the search and reuse of semantic resources (such as ontologies, data schemas and controlled vocabularies) for the development of APIs (Application Programming Interface) on the PDND (National Digital Data Platform).

Semantic resources
Research and use multiple resources, such as controlled vocabularies, ontologies and data schemas, to represent data with semantics and make interchange semantically interoperable.

Tools
The tools to access the semantic resources of the catalog and to validate them. Validation covers both the general description or metadatatation of semantic resources and the structure in the case of API schemas.

Support to institutions
Support for the creation of semantic resources that represent the data of a reference application domain, see the contact section

The catalogue has several main objectives that aim to improve the efficiency and quality of the exchange of data and information. First, one of its purposes is to provide common models and standards that create a shared language and unique classifications to describe the data and information that is exchanged between different systems.
In addition, the catalogue supports the development of interoperable digital services. It provides the semantic tools necessary to create APIs (Application Programming Interfaces), so that different systems can "speak the same language", facilitating the integration and use of services.
Finally, it aims to promote the reuse of public data, standardizing open data to make it more understandable and reusable by developers and citizens. This approach contributes to improving the quality of the data exchanged, thus ensuring the implementation of digital public services that implement the "once only" principle, i.e. sharing data only once to avoid duplication and waste.

Controlled vocabularies are used in different contexts to facilitate the organization and search for information.

• Indexing and information retrieval (the drop-down of an application)
• Categorization and classification
• Standardisation of terminology
• Integration of data from different sources
• Improved user experience when searching for information

Ontologies are used to represent knowledge in a specific domain in a structured way and with defined relationships.

• Improved understanding of a domain
• Improvement of machine interpretation and smarter understanding of data
• Knowledge sharing between applications and systems
• Facilitating the search for a specific domain
• Support of modeling and data analysis
• Support in application development
• Development of intelligent systems (AI) able to reason, interpret and generate knowledge.

Data schemas allow you to describe data models: what are the different fields, how are the data represented, what are the possible values, etc.

• Increased quality of data exchanged
• Improved data modelling and analysis
• Verify that a dataset conforms to a schema
• Automatic generation of documentation
• Generate sample data sets or offer standardized input modules.

The data published in the catalog are provided by contributors, who feed the catalog with their own semantic assets. These contributors may be public entities, i.e. public administrations interested in modelling and publishing their semantic resources, maintaining their ownership and responsibility for content, or representatives of such entities, including private ones.
The ontologies, controlled vocabularies and data schemas are derived from official repositories of the contributing bodies of the Public Administration, thus ensuring reliability and compliance with official sources. Each entity is responsible for the published metadata.

The catalogue is fed through an automated process called harvesting, which collects data from the appropriately configured semantic resource repositories. Contributors create their own repository to publish indexing resources. Subsequently, they can request the activation of the harvesting process by sending a request to info@schema.gov.it. After the configuration procedures are completed, the new resources will be collected and integrated into the catalog.
The harvester checks if there is anything new in the contributor repositories. If it finds changes in repositories, it downloads the updated data, analyzes it, and updates the information in the databases.

The data contained and published in the catalog are semantic assets and by definition do not contain personal data, but only metadata. As a result, the data is distributed in open format and under open license CC-BY 4.0. Any data published in the catalog is also available in the repositories made public by the entities. More information on the Privacy Policy page

Yes, the front-end and back-end components of the catalog are open source and accessible in repositories
https://github.com/teamdigitale/dati-semantic-backend
https://github.com/teamdigitale/dati-semantic-frontend
You can suggest an improvement of the catalog by opening an issue in one of the mentioned repositories.

We work to foster practices that improve interoperability, in all its aspects in particular semantic interoperability.
We want to attract and involve more and more public administrations to publish, consult and reuse existing data models in the catalogue.
We want to effectively engage developers in the semantic domain, to develop semantically interoperable APIs and make documentation easy to understand. Try our schema editor, use it, fork it, improve it.

We want to support the development of API-based digital services that use shared models to ensure comprehensible, structured and easily interoperable data exchanges.

The main objectives of the strategy are:

• Disseminate the importance of semantic interoperability to API providers
• Define and disseminate semantic metadatation indications for API providers
• Improve the semantic quality of APIs exchanged via the PDND, both already published in the PDND catalogue and future ones

If you are a public body and would like to contribute to the catalogue, follow these steps:

• Read the catalogue guide to understand the registration process.
• Explore resources already available in the catalog, to avoid redundancies and evaluate the extent of existing resources.
• Create or use a repository to publish your semantic resources, following the technical guidelines on structure and management described in the catalog guide.
• Send a formal contribution request to info@schema.gov.it, to be supported on semantic modeling or publication support, activating the harvesting process of your data.
• After joining, continue to edit and update the resources in your repository, which will be automatically integrated into the catalog.
• See the operations manual for more details and support.
• Go to the page “How to contribute to deepen”