iCalendar to RDFical: a Semantic Web vocabulary created with community process-lite

Libby Miller, ILRT, University of Bristol

Presentation to Intelligence, Agents, Multimedia Group, University of Southampton, 2003-11-03

ILRT SWAD-Europe EU IST logo

Semantic Web calendaring

I will be talking about a Semantic Web vocabulary for describing events, and in particular

and hopefully ...


Why create a Semantic Web vocabulary for events?

1. To try to solve the personal information disaster

Wouldn't it be great if it was easy to find out what's happening (and in particular, what I'm supposed to be doing)? Why do I have to do this stuff that my computer could do for me?

Why create a Semantic Web vocabulary for events?

To describe and use the connections between events and other things

It would be good to be able to find useful and interesting links between events and other things automatically. Why can't my computer do this for me?

Usecase: events and people

who is coming to this meeting? in what way are they 'expert'? what else have they written or spoken about? what do they look like?

a demo showing attendees at a calendaring workshop

Usecase: events and geographical information

where am I going? how do I get there? where's the nearest { restaurant | hotel | station | ...}?

Dan Connolly's travel itinerary

What do we need to do...

We would like a way of describing, publishing and searching with precision events with these sorts of characteristics, where:

Vocabularies for events, people, places....

Much better is to be able to combine vocabularies easily and devolve the creation of vocabularies where possible.

Why RDF?

RDF (Resource Description Framework) has a model for combining many different vocabularies created independently

RDF is designed for combining vocabularies describing overlapping domains of interest, and for merging, storing and searching data defined in this way.

Event data and the Semantic Web

The Semantic Web will be useful when there's a network effect, so people can build applications using the data available

Creating an RDF vocabulary for events

There is already a standard! - RFC 2445 - iCalendar...but

'Translating' a schema is difficult and slow: especially when you are trying to work out what a group meant when they were writing in their own special language, and translate it to your own special language.

iCalendar in RDF: the wrong way

Reusing existing expert work, and taking into account that many implementations use iCalendar, but:

Decisions made in this translation were often arbitrary and themselves ill-documented

RDFCal: the right way 'community process lite'

A different approach: a syntactic conversion of iCalendar to RDF

Result: testable, automated schema, with community input and documented reasons for decisions

Returning to the usecases

Our initial usecases were:

We are doing this using off-the-shelf RDF tools (e.g. using Jena, RDFLib, Brownsauce, Joseki; also other experimental ones) for

We are just starting to experiment with RDFiCal applications, using RDF tools

We don't have all the answers...


A major problem is identifying events: events don't have URIs:

How can I say: I'm going to the same conference as you are?

Future work

baby steps: data will drive the applications

More information

RDF calendar workshop, including usecases:

RDF calendar wiki:

RDF Calendar workspace:

RDF Calendar mailing list:

This presentation:

Thanks for listening!

RDFiCal: libby.miller@bristol.ac.uk, 2003-11-03