Jelte Bootsma (TNO)

Semantics in Data Spaces: Semantic Treehouse as Vocabulary Hub​

From September 17-19, 2024, SEMANTICS 2024 will be held in Amsterdam. At this conference, we will have the opportunity to present a tutorial on Semantics in Data Spaces. Our session will focus on Semantic Treehouse as a vocabulary hub. This tutorial offers a practical perspective on semantics in data spaces and presents the open challenges in an interactive manner. It includes an introduction to data spaces and the role of a vocabulary hub in data spaces, based on the current knowledge from the Data Spaces Support Centre.

For more information, to register, and to view the planned agenda for the tutorial, please see below or visit the following link: Register here.

Abstract​

Data sharing accelerates innovations within and across sectors, leading to the development of new solutions. For a growing number of companies, this turns data into a strategic asset over which they want to maintain control. The European strategy for data aims to create common European data spaces to ensure Europe’s global competitiveness and data sovereignty. Data spaces are distributed systems designed to facilitate secure and trustworthy data exchanges between participants, emphasizing trust and data sovereignty. One of the crucial aspect in making this happen is semantics, which enables consistent and unambiguous data sharing between participants of a data space. Achieving semantic interoperability is a continuous balancing act between maintaining strict uniformity for consistent and easily understandable data, and accommodating the diverse requirements of different data space participants.

This tutorial offers practical insights into shaping semantics within data spaces, with TNO’s Semantic Treehouse as so-called vocabulary hub as an important means. The tutorial highlights the challenges and presents solutions for achieving semantic interoperability in the context of data spaces.

Semantic Treehouse is designed to maximize the reuse of common vocabularies (semantic standards) to ensure a shared understanding of the data. These vocabularies are assumed to be created through open standardization, meaning that they're created 'by the users, for the users'. Open standardization justifies what is essentially a top-down approach to interoperability: as soon as the standard is done, it is published in a central place and users are expected to comply by aligning their data to it.

However, there are various situations that would benefit from a more 'bottom-up' approach, i.e. where the information flow is reversed. Instead of Semantic Treehouse providing information on what vocabulary to use, users provide information on the usage of their data. This need arises in situation where, for example, there's only a loosely defined community where standards are not yet formed. Or when typical users don't have the resources or knowledge to work with semantic standards and make alignments. To overcome this hurdle, Semantic Treehouse has developed a new functionality that allows users to create an initial vocabulary based on their own sample data.

Sharing data across different sectors holds tremendous value. For example, to achieve EU climate goals, the exchange of carbon footprint data across various sectors is of great importance. Therefore, connecting different data sharing communities in these sectors is essential. However, sharing data across different sectors comes with challenges, as each sector develops its own vocabularies and tools. These vocabularies are not accessible across different sectors, and consequently, thus not being used in other sectors. To brigde this gap, a standardized solution is needed to exchange vocabularies across data sharing communities, enhancing the discoverability of vocabularies across different sectors.

This blog post will address how Semantic Treehouse supported the needs of a data sharing community in creating a new standard. Among the dedicated users of Semantic Treehouse is the SETU foundation, the organization for data standardization of the flexible staffing industry in the Netherlands. Recently, SETU developed the Planning and Scheduling standard, enabling seamless data exchange of planning information between staffing suppliers back-office software, planning tools, and interconnecting planning tools.

For this Planning and Schedulling standard, there was a desire to repurpose HR Open specification whenever feasible. This involved creating multiple message models by carefully selecting elements from the HR Open Model in JSON Schema and incorporating SETU specific additions and restrictions. Furthermore, SETU's goal was also to create schemas in both JSON and XML formats, along with Open API specifications for seamless implementation and validation. The following text highlights how Semantic Treehouse supported the SETU foundation in reaching their goals.

Domain-specific vocabularies are crucial for accurate and consistent data interpretation by different individuals and systems. These vocabularies provide a shared conceptualization of knowledge within a particular domain. We observe the emergence of these vocabularies in diverse formats such as Smart Data Models, HR Open and Open Trip Model, which express their vocabularies in JSON or XML schemas.