Abstract

DAML+oil is a language for the precise description of ontologies, building
upon RDF and XML Schema. It enables you to describe objects (for example
events, people, documents) and their relationships unambiguously. It also
uses references to XML Schema datatypes to describe integers, dates and
other datatypes.
These characteristics of DAML+oil are capable of describing aspects of 
SkiCal objects such as price, age restrictions, start and end dates and
times with precision and flexibility. SkiCal makes for a practical and
useful potential application of DAML+oil. In our presentation we describe
the process of formulating SkiCal in DAML+oil. 
SkiCal is an extension of the iCalendar mime-directory standard used in
most major desktop and PDA Calendaring and Scheduling applications.
(RFC2445, RFC2446, RFC2447) 
SkiCal defines the ontology of 'timespending', the domain of information
significant to the interaction of people and resources.  The core
technology of SkiCal is the WHA-machine; the structuring of information
based on the 6 common interrogatives; WHAT, WHEN, WHERE, WHOW, WHY, and
WHO.
Publicly accessible directory information, such as yellow pages, event
calendars, product catalogues, classified ads, academic schedules,
financial listings and their like, provide for rational access to
information. These directories have evolved from paper-based to digital
based media, significantly extending range and effectiveness. 
Personal Information Management; the collection of address book,
scheduler, notepad and accounting tools has also undergone a transition
into the digital domain, initially only as computer-enhanced gadgetry but
now increasingly hooked up to or integrated with a communications terminal
often leading to the internet.
How will these two entities, the public directory and the private or
corporate digital assistant interact and synchronize with each other
efficiently in the future? 
A typical SkiCal interaction could be an eventbot surveying a directory of
all available resources in a physicl space.  The owner of the eventbot
wants to decide how to best spend her time on a Saturday afternoon. Her
bot knows quite a bit about her preferences but also that she is open for
surprises and into exploring the unknown.
The SkiCal directory is much like a yellow page telephone catalogue - only
it is enhanced with information that previously would never find its way
into a telephone catalogue.  Most specifically dates and times are
represented so that the user will know not only what resources are open or
closed but also about service levels and special offers that vary in time
(including transportation services)
The directory will also show short term and singular events that are more
typical to the calendar sections of newspapers or community bulletin
boards.
Requirements made on resources by users or requirements made by resources
upon potential users are also represented in the directory.   
Since the ontology of SkiCal is shared by both the potential time spender
and the resources offered - a high degree of synchronization is possible.  
Up until the development of DAML+OIL much of the WHA markup was awkward to
express in mime-directory or XML-RDF syntax. 
Our session will present a step-by-step account the process of defining
the SkiCal Ontology in DAML+OIL, illustrating both the advantages and
disadvantages entailed.