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Tools

Ontology Browser

A demo of the Star Wars Ontology is available to browse.

Classes, properties, individuals etc can all be browsed to understand the structure of the ontologies. Cloud views can give a quick feel for where the detail is eg instance usage

This demo is a running on a custom branch, paired version of the ontology browser, specifically loaded with all.owl.ttl.

It is hosted on a cheap tier web server, so please don’t expect extremely fast responses for some queries.

Querying with Pellet (Openllet) reasoner is possible on the DL Query page.

This also supports set subtraction between queries which is useful where closure is not available. Essentially mapping to “A is true but B is not known” (weaker than “A and not B”).

Who worked for the Jedi Order that was not a Jedi? Cid, who was an informant

You can even switch to the Dark Side if you prefer.

Protege

We used Protege to build this ontology

Reasoning

Use the Pellet reasoner

• Select Pellet from the Reasoner menu.
• Select Start Reasoner to show inferences in the model

Other reasoners are available, but each has different performance issues

Protege Known Issues

• Using Turtle as a file format means changes to base cannot be saved if other ontologies loaded
  • bug raised - https://github.com/protegeproject/protege/pull/1025
• Selection model and entity focus is very buggy
  • clicking/finding an entity frequently does not navigate to that entity
  • sometimes the focus changes when adding relations/subclass axioms

Protege Features

DL Query Tab

For off the cuff queries as simple as year value -22

Individual Hierarchy Tab

after

• Select hide orphans
• Navigate the after tree with inverse property
• ideally use during for children and before for sibling order

memberOf

location

• Temporarily remove Transitive(location) and navigate through from Galaxy
  • ships make this messy

Issues

• Requires the reasoner - would be nice to also see asserted tree
  • eg transitivity makes the tree messy with individuals showing at all levels
• lots of duplicate nodes in top level of tree - bug?
• ideal if the nodes worked for selection, but they don’t
• we’d require a more advanced tree ideally that allows ordering of siblings by a property (eg after)

OWLDoc

Export HTML rendering of the ontology for browsing (read only/asserted only). Seems bugged now.

• html frames not working (in Chrome at least).
• entity pages contain lots of assertions about other entities - looks like this is due to the ontology being modularised.

WebProtege

https://webprotege.stanford.edu/

More limited (eg cannot use a reasoner?) But can import multiple ontologies and looks to have good multi-user support now.

https://protegewiki.stanford.edu/wiki/WebProtegeUsersGuide#Viewing_and_Editing_OWL_2_Ontologies