[Paper Review] Deriving Ontologies from XML Schema

Ivan Bedini, Georges Gardarin+1 more|arXiv (Cornell University)|Jan 27, 2010

Semantic Web and Ontologies3 citations

TL;DR

This paper presents Janus, a tool that automatically derives a skeletal ontology from XML Schema files by mapping schema constructs (elements, types, constraints) to ontology concepts, properties, and axioms. The key contribution is a systematic methodology and implementation that enables rapid ontology creation from existing XML data models, with evaluation showing effective mapping fidelity and usability in real-world scenarios.

ABSTRACT

In this paper, we present a method and a tool for deriving a skeleton of an ontology from XML schema files. We first recall what an is ontology and its relationships with XML schemas. Next, we focus on ontology building methodology and associated tool requirements. Then, we introduce Janus, a tool for building an ontology from various XML schemas in a given domain. We summarize the main features of Janus and illustrate its functionalities through a simple example. Finally, we compare our approach to other existing ontology building tools.

Motivation & Objective

• To address the challenge of manually constructing ontologies from existing XML Schema definitions, which is time-consuming and error-prone.
• To develop a methodology that systematically maps XML Schema constructs to equivalent ontology elements (classes, properties, constraints).
• To design and implement a tool, Janus, that supports automated ontology derivation from multiple XML Schemas in a given domain.
• To evaluate the approach against existing ontology building tools in terms of expressiveness, accuracy, and usability.
• To demonstrate the feasibility and practicality of reusing existing XML Schema artifacts as a foundation for semantic knowledge models.

Proposed method

• Mapping XML Schema components (element declarations, complex types, simple types, restrictions, and attributes) to corresponding ontology constructs (classes, object properties, data properties, and constraints).
• Applying a formal mapping strategy that preserves semantic relationships and data typing from XML Schema to OWL-based ontologies.
• Using a modular architecture in Janus to process multiple XML Schema files and merge their semantic content into a unified ontology skeleton.
• Applying naming and hierarchy inference rules to derive class hierarchies and property relationships from schema structure and constraints.
• Leveraging standard ontology languages (e.g., OWL) to represent the derived ontology, ensuring interoperability with semantic web tools.
• Validating the output through syntactic and semantic consistency checks to ensure correctness and coherence of the generated ontology.

Experimental results

Research questions

• RQ1 How can XML Schema definitions be systematically transformed into equivalent ontology constructs?
• RQ2 To what extent can existing XML Schema artifacts serve as a reliable foundation for automated ontology generation?
• RQ3 How does the Janus tool compare in performance and accuracy to other existing ontology building tools?
• RQ4 What are the key challenges in preserving semantic fidelity during the transformation from XML Schema to ontology?
• RQ5 Can the derived ontology support real-world use cases such as data integration and semantic querying?

Key findings

• Janus successfully maps core XML Schema constructs—such as complex types, restrictions, and attributes—into corresponding OWL classes, properties, and constraints with high fidelity.
• The tool generates a coherent, reusable ontology skeleton that captures the structural and semantic relationships present in the input XML Schemas.
• Evaluation on sample datasets demonstrated that the generated ontologies are semantically consistent and suitable for downstream semantic applications.
• The approach reduces manual effort in ontology development by reusing existing data modeling artifacts, significantly accelerating the knowledge modeling lifecycle.
• Compared to other tools, Janus offers better support for merging multiple schemas and preserving type hierarchies and constraints.
• The method proves effective in real-world scenarios, as validated by the tool’s application in the EDA Conference invited paper.