The Easy Conditions widget is implemented as an alternative restrictions view in the OWL Classes tab. It is an adaptation of a custom widget built for a group of users that do not require the full expressivity of OWL so does not (and is unlikely to) allow the same level of expressivity as the logic or properties views. For example, currently only necessary restrictions are shown.

It is intended to be useful for people that are used to seeing entity-relation diagrams and are therefore used to a cardinality view of the world. Each row may group and display several restrictions at once (commonly min and max cardi).

WARNING - the Easy Conditions widget creates Qualified Cardinality Restrictions (QCRs) by default - which are not currently part of the official OWL1.0 specification (but are currently supported by Protege-OWL). Using this widget is likely to create OWL-Full ontologies

for Protégé 3.2 beta build 2 (beta)

Last updated: 11th May 2006

To install:

• remove any old version of the easy conditions widget from the Protégé plugins folder
• unzip the download into the plugins folder

To use:

• The view will automatically be selectable on the bottom right of the OWL Class Tab
• Adding a restriction defaults to adding a min cardi 1 (same as an existential restriction) along the given property.
• Inherited restrictions are partially greyed out and not editable (future work will allow these to be "narrowed").
• Ticking the "close" checkbox on the right of a restriction will attempt to create (or update) a closure axiom for all of the appropriate restrictions along that property.
• The widget tries to identify rows whose fillers are missing from closure - these are marked in red to help the user identify the mistake. Ticking the box will fix this.
• Frequent switching between views will help the user understand the results of the actions they perform in the widget.
• By default, only named classes can be given as fillers - although it will show class expressions. This and other options can be changed by editing the custom.properties file in the easyconditions folder (explanations given in the file).
• Anything that causes a class to be inexpressable in this view (eg defined classes) should cause the widget to shift temporarily to the logic view.

Author: Nick Drummond

Institution: The University Of Manchester

The Easy Conditions Widget is under active development.

All comments and suggestions/feature request will be appreciated!

Please check our bugtracker for current status.

The Easy Conditions Widget is made available under the GNU Lesser General Public License

Copyright © 2006, The University Of Manchester

This work is funded by JISC.

We work in collaboration with partners from Stanford University and other institutions in the UK (see CO-ODE homepage).

Special thanks to Holger for his achievements with the OWL plugin.