The slides for my keynote at RuleFest 2011 are here.
Excellent presentations on complex event processing by Paul Vincent of TIBCO and Mauricio Salatano who showed simple, effective integration of events and rules using Drools. Mauricio’s was a good demo and Paul’s slides are worth perusing once they go on-line. (Some comments from Carlos about Paul’s, Mauricio’s, and my presentations are here, here and here, FYI.)
Christian St. Marie and Hugues Citeau each of Ilog (IBM) on improving RIF support in JRules and the worthy ONTORULE project, respectively. Both presentations confirm the gulf between production rules and sufficient logical expressiveness to support natural language or natural logic knowledge management, but IBM is clearly aware of and trying to address the challenges raised in my presentation.
The standard for defining ontologies these days is OWL and Protege. Unfortunately, OWL lacks any notion of exceptions in inheritance or any other notion of defeasibility.
So, although you may want to say that birds fly, you’re ontology will be broken (or become much more complicated) when you realize there are birds that can’t fly, such as penguins or ostriches, or even sick or injured birds.
Practically speaking, you need something like courteous logic or the defeasibility in SILK to handle this (or any 1980s expert system shell or even earlier frame system). OWL is very hard on mortal man (e.g., mainstream IT) in this regard.
How can I tell OWL that a pronoun is a noun but that pronouns are a closed class of words, unlike nouns, verbs, adjectives, and adverbs (in general). Well, I’ll have to tell it about open-class nouns versus closed class nouns. What a pain!
This is why we use Protege primarily as a drafting tool and, for example, SILK, to do reasoning. Non-defeasible description logic and first-order reasoners are difficult to get along with, in practice (and make sustainable knowledge repositories too difficult – which inhibits adoption, obviously).