This article illustrates how to enhance data interoperability among Public Administrations (PPAA) by leveraging the publication of e-services based on Semantic Web (SW) technologies such as ontologies, controlled vocabularies, and data schemas, which, through standard languages like OWL [6], RDF[12], and SPARQL [5], ensure harmonization, integrability, and unique semantics for representing administrative data. Furthermore, the potential benefits of implementing semantic e-services through Ontology-based Data Management (OBDM), a data governance methodology that enables data services through ontologies, decoupling their implementation from the physical data sources of PPAA, are discussed. Additionally, the advantages for PPAA of data exchange through semantic e-services utilizing concepts published in the Schema platform, developed by the National Data Catalog project funded through PNRR funds, will be highlighted in the presented use case.
provides semantic clarity to administrative data through an extensive network of Ontologies, ConAs part of the investment initiatives delineated trolled Vocabularies, and data schemas [7]. These within the National Recovery and Resilience Plan are facilitated by standard languages such as OWL, (PNRR), which is part of the Next Generation EU RDF, and SPARQL, ensuring harmonization, in(NGEU) program, a measure concerning the dig- tegrability, and a unified semantics to represent ital transition of Public Administrations (PPAA) administrative data information. in data management and interoperability has been The adoption of these standards ensures the accesdesignated referred to as the National Digital Data sibility, reusability, and inferential capacities across Platform (PDND). This platform acts as the tool data originating from various sources, processes, to centralize the authentication and authorization and domains. To fully realize the benefits of these methods for data exchange among parties. There- technologies, data ideally should be accessible via fore, PDND manages the authorization phase of ac- standard data access protocols, such as SPARQL cessing the Application Program Interfaces (APIs), [5], the W3C’s reference language for querying RDF while PPAA set up their automatic connectors to datasets and OWL ontologies. Among the solumake data accessible and interoperable, promot- tions to ensure adherence to these protocols is ing their sharing among administrations, as well the Ontology-based Data Management (OBDM) as between citizens and enterprises. Particularly, paradigm [8], which advocates for a virtual approach this approach avoids citizens from having to pro- to data governance, and consequently, data access, vide the same information multiple times to various through ontologies. administrations. The rest of this paper is structured as follows. In
Additionally, investments aimed at enhancing Section 2, we will introduce Schema, the National data interoperability within the PDND also encom- Data Catalog for semantic interoperability, and expass the development of Schema, the National Cat- plain how the semantic assets published therein can alog of data for semantic interoperability, which assist PPAA in the implementation of semantic eservices according to data schemas, leading to full Ital-IA 2024: 4th National Conference on Artificial In- data interoperability. Section 3 will illustrate the potelligence, organized by CINI, May 29-30, 2024, Naples, tential benefits of implementing e-services through Italy OBDM, primarily by decoupling the service layer *Corresponding author. from the data layer. In Section 4, we will provide †$Thaersaecraiu@tihstoarts.icto(nRtr.iMbu.teAdraecqrui)a;lldya.rio.frisardi@istat.it an example, through a use case, of the benefits (D. Frisardi); radini@istat.it (R. Radini); guaranteed to individuals by data interoperability. santarelli@obdasystems.com (V. Santarelli) 0009-0005-4399-7589 (D. Frisardi) © 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
Person : t y p e : o b j e c t d e s c r i p t i o n : h t t p s : / / w3id . o r g / i t a l i a / onto /CPV/ Person x−j s o n l d −c o n t e x t : . . . tax_code : h t t p s : / / w3id . o r g / i t a l i a / onto /CPV/ taxCode d a t e _ o f _ b i r t h : h t t p s : / / w3id . o r g / i t a l i a / onto /CPV/ d a t e O f B i r t h family_name : h t t p s : / / w3id . o r g / i t a l i a / onto /CPV/ familyName
enhancement, as delineated and overseen by the National Data Catalog (NDC) project [7], the development of the portal, Schema, aims to make the semantic resources of PPAA available. Schema catalogs semantic assets, such as ontologies, controlled vocabularies, and data schemas, making them searchable, reusable, and thus fostering interoperability. The semantic structures of Schema enable the definition of a unified semantics that . . . harmonizes data representation and facilitates in- p r o p e r t i e s : formation exchange for Italian PPAA. For further tax_code : information about Schema and the available seman- $ r e f : "#/ components / schemas / tic assets, additional online resources can be found TaxCode " in Appendix A. d a t e _ o f _ b i r t h :
By leveraging ontology semantics, coherence and f o r m a t : d a t e
consistency in data are ensured, significantly en- t y p e : s t r i n g
hancing interoperability. Within ontologies, there is p a t t e r n :
uniformity in the description and referencing of en- [
Data schemas become an essential tool for PPAA . . . to expose their data and facilitate communication TaxCode : through shared channels, exploiting the fundamen- t y p e : s t r i n g tal principle of a unified semantics. The strength of d e s c r i p t i o n : h t t p s : / / w3id . o r g / data schemas lies in their ability to expose the data i t a l i a / onto /CPV/ taxCode structure and enforce type and format constraints, . . . ensuring not only syntactic but also semantic inter- where the type is reported, as well as the URI operability, targeting entities and concepts defined pointing to the semantic resource is included in within ontologies and controlled vocabularies [10]. description. All the properties, whether re
In the context of e-services, the accurate defini- quired or necessary for the service, are inserted tion of data schemas plays a fundamental role in after specifying the corresponding semantic referensuring data coherence and complete interoper- ence. Thus, it can be observed how data schemas ability. Establishing a shared ontological semantics, incorporate format and type constraints, as well therefore, becomes crucial to guarantee a uniform in- as references to other components (e.g., tax_code), terpretation of data by all involved parties. Through which will then reference a semantic resource defina proper implementation of data schemas, e-services ing its concept. Currently, JSON-LD standard [13] become essential tools for promoting the efective does not allow to define in a unique way the conutilization of semantic technologies within the realm text for primitive values, i.e. string, and in such of public administration. cases it is necessary to adopt an ad-hoc shared strat
The data schema format for the e-service must egy. More detailed data schemas are available in adhere to the specifications of a YAML file [ 2] (if Appendix A. version 3.0 of OpenAPI is utilized, the YAML file should be named with an extension oas3.yaml).
Within the e-service data schema, the main com- 3. Implementation of e-services ponents of the service in question must be defined, with OBDM taking into account the semantic references of ontologies and controlled vocabularies. An example of how the data schema should be structured to define the concept of “Person” is provided below, showcasing some of the key commands: Sapienza University of Rome and by OBDA Sys- with mappings serving the role of reconciliation betems1. Its aim is the integration and governance of tween these levels. In this scenario, the ontology data stored in an organization’s information system and corresponding mappings to the sources provide through an ontology. The purpose of this approach not only a tool for data access but also a common is to create a single conceptual access point to the basis for documenting an enterprise’s information organization’s information assets, enabling the con- assets. This approach brings significant benefits ceptual realization of all data governance services for governance and management of the information within a complex system. system.
Indeed, OBDM can be viewed as a form of virtual E-services represent an opportunity to leverage data integration. However, it is based on the notion the wealth of shared ontological models and conof replacing the global schema, which represents the trolled vocabularies in Schema, not only as tools for unified view of the domain, with a conceptual and conceptual sharing, but also as a means of semantiformal representation formulated through an ontol- cally accessing data according to standardized and ogy expressed in a logical language. This choice en- shared models. The value added by implementing sures that the integrated view ofered by an OBDM e-services through OBDM techniques is two-fold. system is not limited to a structure accommodating Firstly, it resides in the capability to decouple data from sources but constitutes a semantically the implementation of e-services from the physical rich description of the relevant concepts within the sources of repositories that host the data of PPAA. domain of interest and the relationships between In this scenario, the realization of e-services could them. Similarly to how it occurs in data integra- potentially be accomplished solely through the artiction systems, conceptual relationships, or mappings, ulation of requirements or queries on the ontological are utilized to establish semantic correspondences models published on Schema by the data-owning between the global schema and the data in the PPAA. This approach delegates the task of medisources. ating with the data structures of individual PPAA
When seeking information, a query is expressed to the mappings, while the ontological reasoning
on the ontology (rather than on the information engine is entrusted with leveraging ontologies and
system’s databases), and the correspondences estab- mappings to translate the ontological requirement
lished between the data and the ontology’s concepts into queries on the physical data.
enable the ontological reasoning engine [
The latter aspect not only formally describes the tructural ones. OBDM, on the other hand, ofers enterprise’s information model but also serves as a a solution distinct from this scenario, favoring a means to embrace a declarative approach to data virtual approach to data access, where queries exgovernance. Through the explicit delineation of pressed in SPARQL on the ontology are transformed the domain representation, knowledge reusability into SQL queries on the physical sources at query is achieved, a feat not achieved when the global time. schema merely provides a unified description of the The decision to employ OBDM presents clear underlying sources. advantages both in terms of e-service implementa
OBDM systems generally have a common struc- tion, utilizing standard Semantic Web languages for ture divided into three layers or tiers: ontology, map- querying ontologies, i.e. SPARQL, and in terms of pings, and data sources. The distinction between their maintenance and evolution. ontology and data sources reflects the separation The decoupling from the physical layer would between the conceptual or semantic level, which allow isolating the e-service layer from the usual dyis presented to users, and the logical and physical namics of reorganization, restructuring, distribution, level of the information system, stored in the sources, or replication typically encountered by databases in information systems, particularly in the case of 1www.obdasystems.com large organizations. In light of these developments, adjustments to ensure the consistency of data sharing services would be confined to the mapping layer, thus modifying the assertions that express the correspondences between elements of the data layer and those of the semantic layer.
sections, we aim to introduce an illustrative use case
of data interoperability among PPAA and a valuable
aid to citizens by implementing the principle of once
only [
This use case involves an exchange of information between e-services exposed by the relevant PPAA. For its modeling, as introduced in Section 2, a portion of the Schema semantic network is utilized, particularly the core Location (CLV), People (CPV), and Organization (COV) ontologies, along with domain-specific ontologies, such as the Italian Learning Ontology (Learning), Resident Population Ontology (RPO), and the Cultural Heritage Ontology (CulturalHeritage). All the reported ontologies are available in Appendix A, while in Figure 1 there is a portion of the semantic network.
To achieve this, the Ministry of Culture, MiC, can provide an e-service, S12, to a cultural institution (e.g., a museum), which, given the unique identifier of a person (tax code) and the municipality where the cultural asset subject to promotion is located, retrieves: i. an e-service, S1, exposed by the National Register of the Resident Population (ANPR) system, which returns a confirmation if the person’s current municipality of residence matches that of the cultural asset; ii. an e-service, S2, provided by the Ministry for Universities and Research (MUR), conifrming that the person is a student enrolled in a High-Level Education course.
An example of the YAML code configuration for the e-service S1 is provided below, with the key commands: components : schemas :
R e g i s t e r e d R e s i d e n t P e r s o n : x−j s o n l d −c o n t e x t : RPO: h t t p s : / / w3id . o r g / i t a l i a /
onto /RPO/ tax_code : h t t p s : / / w3id . o r g /
i t a l i a / onto /CPV/ taxCode c u r r e n t l y _ r e g i s t e r e d _ r e s i d e n c e : " @id " : "RPO: c u r r e n t l y H a s R e g i s t e r e d
R e s i d e n c e I n " " @context " : " @base " : " h t t p s : / / w3id . o r g / i t a l i a / c o n t r o l l e d − v o c a b u l a r y / t e r r i t o r i a l − c l a s s i f i c a t i o n s / c i t i e s " t y p e : o b j e c t d e s c r i p t i o n : h t t p s : / / w3id . o r g / i t a l i a / onto /RPO/
R e g i s t e r e d R e s i d e n t P e r s o n r e q u i r e d : − tax_code p r o p e r t i e s : taxCode : $ r e f : "#/ components / schemas /
TaxCode " c u r r e n t l y _ r e g i s t e r e d _ r e s i d e n c e : t y p e : s t r i n g enum : [ . . . ] example : ’058103 −(1871 −01 −15) ’ TaxCode : t y p e : s t r i n g d e s c r i p t i o n : h t t p s : / / w3id . o r g /
i t a l i a / onto /CPV/ taxCode
The addressing to the tax code concept is ensured by the URI identifying the concept (https://w3id.org/italia/onto/CPV/taxCode), simi- quently data, can fully achieve the objective of “diglarly to the use of the controlled vocabulary of cities italization, innovation and security in the Public (https://w3id.org/italia/controlled-vocabulary/ Administration.” This could be the prompting for territorial-classifications/cities) for current reg- the digitalization of the entire Italian country. istered residence. Therefore, unique semantics emerge as a fundamental tool that, in the reported use case, enables interoperability among the 3 References e-services.
In Figure 2 there is an illustration depicting the main components, and their connections through e-services, in the use case.
The sources for data schemas in Schema: • Schema • INAIL • INPS • CLV • COV • CPV • CulturalHeritage • L0 • Learning • RPO