Friday, May 16, 2008

Justin Betteridge - Friday May 23rd

Please join us for an upcoming talk.

Lunch will be provided by Yahoo!

Linguistic Pattern Learning for Web Information Extraction

Who: Justin Betteridge
When: Friday, May 23rd, 12:00pm
Where: NSH 3002

Most approaches to automatically extracting structured information from the web
rely on surface text patterns. However, the manner in which such patterns are
defined, learned, and employed in the larger system varies with each case. In
this talk, I will outline the spectrum of previous work in this area and argue
for a linguistically-motivated definition, a hybrid heuristic/classifier-based
assessment, and a multi-purpose employment of textual patterns in the context of
Web Information Extraction (WIE). I will also give preliminary results from
adopting such an approach in our WIE system.

Wednesday, May 7, 2008

Grace, Hui Yang - Friday May 16th

Please join us for an upcoming talk.

Lunch will be provided by Yahoo!

Ontology Learning by Supervised Hierarchical Clustering

Who: Grace, Hui Yang
When: Friday, May 16th, 12:00pm
Where: NSH 3002

This work makes novel use of supervised clustering as the basic
framework to construct concept ontology interactively or
automatically. Supervised hierarchical clustering is used to
organize ontology fragments, which are identified by techniques in
natural language processing and information retrieval, into
hierarchies. At each clustering iteration, a distance metric is
learned from the clustering given by either pseudo or real
feedback. K-medoids clustering with sampling is then used to group
the concepts at the higher level. A web-based cluster naming
algorithm is also presented. By conducting a user evaluation, the
system is shown to be effective to save human efforts in the
interactive runs. Both automatic and interactive runs of the
experiments show that the approach is effective.