August 17, 2005
Generic Soft Pattern Models for
Definitional QA
27/28
Conclusions
•Proposed Bigram model and PHMM
model
–Generic in the forms
–Systematic parameter estimation
by EM algorithm
•These two models can be applied
to other applications using surface text patterns
–Soft patterns have been applied
to information extraction (Xiao et al., 2004)
–PHMM is more flexible in dealing
with gaps, but requires more training data to converge