WP4 Print
WP4 - Ontology access, processing, and usage

Workpackage number
Start date or starting event
06/2006 End date 08/2007
Activity type
RTD/Innovation activities
Participant id
Person months
4 2.5
3 10
Description of work
TASK 1: Formalization of tasks for ontology access, processing, and usage
In this workpackage we concentrate on all those tasks introduced in WP1 that deal with single ontologies
when they are already in operation. Based on the results of WP1 and WP2, we will identify the reasoning
services that are needed to support the tasks relevant to accessing, processing, and using an ontology.
These reasoning services comprise both services that use mainly intentional knowledge, and services
that use mainly extensional knowledge. The first ones may rely in part on the work done in WP3. The
latter instead, deal with data and with the fact that this data is only available when the ontology is in
operation. These identified reasoning tasks will also be related to the increasing need of customizing
part of the knowledge in an ontology to the needs of multiple kinds of clients. Therefore, methods and
services making use of the introduced reasoning services will be developed, so as to support multi-client
access, processing, and usage of ontologies.
TASK 2: Development of techniques for ontology access, processing, and usage
Our aim is to understand the computational properties of the identified reasoning services when used
within the framework developed in WP2. With respect to the work done in WP3, for those reasoning
tasks requiring the access to large amounts of data, special care will be placed in analyzing the computational
complexity with respect to the data, and possibly introducing semantically well-characterized
approximations that allow for lowering data complexity. Reasoning services for handling additions and
retractions, including forms of induction and abduction, will be studied. Particular care will be placed
for supporting incremental changes of ontologies.
TASK 3: Implementation of the techniques for ontology access processing, and usage
The obtained algorithms for the relevant reasoning services will be implemented in prototype software
tools. Specific techniques for dealing with large amounts of data maintained in an ontology will be developed.
In particular, techniques that allow clients to (i) incrementally receive “easy results early” and (ii)
to anticipate changes in resource consumption for computing “remaining” results. In this context, we will
also investigate whether worst-case optimal algorithms for standard inference problems are also practical
in the sense that they are amenable to advanced optimization techniques (i.e., show good average-case
complexity, maybe without optimality in the worst-case). This concerns, for instance, caching (tradeoff
between memory and time consumption), data structures for search control, query answering strategies,
and resource management policies (e.g., for index computation, server allocation).
D10 (08/2006) – Tasks for ontology access, processing, and usage (Report)
The report will discuss in detail the reasoning services needed for ontology access, processing, and usage
tasks. It will also describe how these reasoning services will be used in methods and services supporting
such activities.
D18 (06/2007) – Techniques for ontology access, processing, and usage (Report)
The report will summarize the reasoning techniques that realize the reasoning services identified as fundamental
for ontology access, processing, and usage, and will report on their computational properties.
D21 (08/2007) – Software tools for ontology access, processing, and usage (Prototype)
Prototype software tools that implement the reasoning services supporting the tasks for ontology access,
processing, and usage will be delivered. An accompanying report will describe the optimization and
heuristic techniques adopted.
Milestones and expected results
M4 (08/2007) – Techniques and tools for single ontology offline and online tasks
The expected results of this workpackage are a set of reasoning techniques and tools for realizing access,
processing, and usage of a single ontology.

2005-2007 TONES - Thinking Ontologies