Contrastive Explanations for ABox Entailments

Project Overview

This project implements a reasoning system for computing contrastive ABox explanations over OWL ontologies, inspired by the methodology presented in the research paper:

“Can You Tell the Difference? Contrastive Explanations for ABox Entailments” (KR 2025)

It aims to answer questions like:

Why is individual a an instance of concept C, but individual b is not?

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What This Code Does

• Generates random, complex OWL class expressions over a given ontology.
• Identifies fact individuals (satisfy the expression) and foil individuals (do not).
• Constructs Contrastive Explanation Problems (CEP) by pairing a fact, a foil, and a target class.
• Computes contrastive explanations:
  • q₁ (commonality): shared assertions between fact and foil.
  • q₂ (difference): what fact has that foil lacks.
  • Conflict set: axioms preventing foil from satisfying the class.
• Reports statistics on explanation size, conflict size, runtime, and synthetic individuals introduced.

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Input JSON Format

You can download an example input JSON file here:
family_json_input.json

Field Explanations

The JSON file contains the following fields:

• ontology_input_file_path: Path to the OWL ontology to be loaded.

• output_file_path: Base path for saving the results file (text or JSON).

  • Example text output file: family_output.txt
  • Example JSON output file: family_output.json

• reasoner: Choice of OWL reasoner (HERMIT or ELK).

• output_format: Format of the output file (text or json).

• experiments: Array of experiments, each containing:

  • class_expression: Manchester OWL syntax expression to evaluate.
  • facts: List of individuals that satisfy the class expression.
  • foils: List of individuals that do not satisfy the class expression.

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Running the Experiment

You can run the experiments either via the provided .bat scripts or directly from the command line.

Command Line Example

java -cp <classes_path>;<jar_path> anonymized.contrastive.experiments.FactFoilFileWriter <input_json_file>

Example .bat file content:

JAR File Explanation

• The JAR file (contrastive-explanations-0.3-SNAPSHOT-jar-with-dependencies.jar) contains:

  • All compiled project classes.
  • All dependency libraries (OWL API, ELK, HermiT, EVEE, SLF4J).

• It allows running the experiments standalone without manually adding classpath dependencies.

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Explanation Components

• q₁ - Commonality: ABox assertions shared between fact and foil individuals.
• q₂ - Difference: Assertions that hold for the fact but not for the foil.
• Conflict set: Axioms preventing the foil from satisfying the class.

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Notes & Tips

• Ontologies with >10,000 axioms are skipped for performance reasons.
• Unsupported constructs (e.g., individual-based TBox axioms, sameAs) are filtered.
• Random seed is fixed (0) for reproducibility.
• Logging is suppressed by default — enable SLF4J if needed.

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Contributions & Contact

We welcome contributions:

• Submit pull requests.
• Open issues for bugs or suggestions.
• For academic inquiries or collaborations, contact the project maintainers via GitHub.