Ontologies are now widely used for representing information regarding a universe of discourse. Many ontology modeling environments have been created, which though provide built-in support only for basic data types, while support for other information structures, although possible to some extent, is not adequately handled. This work is an extension of the Protégé tool to accommodate the modeling and presentation of:

• entity history, i.e. past values of properties and/relationships; each such value is timestamped with the period that it was (or will be) valid in the real world. To this end, the presented extension provides:
  1. integrated support for data types expressing time quantities – more specifically dates (individual points in time) and periods (anchored segments of the time axis).
  2. data types for storing histories of properties of different types (strings, integers, floats, booleans and instances [i.e. relationships]).
• weighted data, i.e. data where each value is associated with a real number, its weight. This can serve as a degree of confidence for fuzzy/uncertain data or for any other application-defined purpose.

The extension can be used in contexts that the modeling of entities’ history or representation of weights is important, such as historical archives, museums, fuzzy and uncertain data management etc.

In order to install the extension you need to perform the following steps:

1. Download Protégé Version 3.1.1 from the Protégé site (http://protege.stanford.edu)
2. Install the Protégé software following the instructions provided by the Protégé team
3. Download the wt-protege.zip file; this is the compiled, ready-to-run version of the extension. URL http://sdbs.cst.uop.gr/files/wt-protege.zip
4. Unzip the downloaded wt-protege.zip file in the Protégé installation directory replacing the protege.jar and protege_text.properties files therein (in Windows-based systems, the default location is C:\Program Files\Protege_3.1).

You may now run Protégé as usual, and the extended version will be loaded.

Documentation is available in both Microsoft Word and PDF format:

• Mircosoft Word (108K) Download
• PDF (196K) Download

This work should be cited as: Vassilakis, Costas, Lepouras, George, Katifori, Akrivi (2007). wt-Protégé – An Extension for Protégé Supporting Temporal and Weighted Data, Technical Report TR-SSDBL-07-001, September 2007, Tripoli, Greece

Downloads for the wt-Protégé project:

• wt-protege.zip is the compiled software for managing temporally enhanced ontologies
• wt-documentation.doc is the project documentation in Microsoft Word for Windows format
• wt-documentation.pdf is the project documentation in PDF format