Skip to content
Competency question Language for specifying Requirements for an Ontology
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.


Competency question Language for specifying Requirements for an Ontology and similar artefacts


Competency Questions (CQs) for an ontology aim to demarcate the scope of its contents. They are sparsely used in ontology development, however, likely because there is no tooling and automation for writing them and evaluating them against the ontology, therewith hampering their effective use. Regarding support for authoring CQs, there are a few question templates based on informal analyses of a small number of competency questions, hence, with limited coverage of question types and sentence constructions. No Controlled Natural Language exists to guide the domain experts to author CQs.

We aim to fill this gap by proposing the CLaRO template-based Controlled Natural Language resource to author CQs. For its design, we exploited a new dataset of 234 TBox-level CQs that had been analysed automatically into 106 patterns, which we analysed on their shape, commonalities, and recurring patterns, which was subsequently used to design a template-based CNL, with an additional XML serialisation. The templates also are annotated with a set of human-friendly aspects so that a user may select, e.g., "a CQ template that asks for difference" to narrow down formulating a CQ.

The CNL was evaluated with a subset of questions from the original dataset and with two sets of newly sourced competency questions. The coverage of CLaRO, with its 93 main templates and 41 linguistic variants, is about 90% for unseen questions. CLaRO has the potential to facilitate streamlining formalising ontology content requirements and, given that about one third of the competency questions in the test sets turned out to be invalid questions, assist in writing good questions.

Resources on this github repo

This repository has the following resources:

  • the 134 templates of CLaRO, in xml and in txt
  • the data and results of the CLaRO evaluation
  • a data file with annotations how CLaRO was created
  • a tool to author questions using the CLaRO templates

Citing CLaRO

full reference TBA in the upcoming days, as well as the zenodo DOI.

Availability for use and reuse

CLaRO is available under a CC-BY licence

You can’t perform that action at this time.