Alexander Clark


2021

pdf bib
Strong Learning of Probabilistic Tree Adjoining Grammars
Alexander Clark
Proceedings of the Society for Computation in Linguistics 2021

pdf bib
Consistent unsupervised estimators for anchored PCFGs
Alexander Clark | Nathanaël Fijalkow
Proceedings of the Society for Computation in Linguistics 2021

2020

pdf bib
Consistent Unsupervised Estimators for Anchored PCFGs
Alexander Clark | Nathanaël Fijalkow
Transactions of the Association for Computational Linguistics, Volume 8

Learning probabilistic context-free grammars (PCFGs) from strings is a classic problem in computational linguistics since Horning (1969). Here we present an algorithm based on distributional learning that is a consistent estimator for a large class of PCFGs that satisfy certain natural conditions including being anchored (Stratos et al., 2016). We proceed via a reparameterization of (top--down) PCFGs that we call a bottom–up weighted context-free grammar. We show that if the grammar is anchored and satisfies additional restrictions on its ambiguity, then the parameters can be directly related to distributional properties of the anchoring strings; we show the asymptotic correctness of a naive estimator and present some simulations using synthetic data that show that algorithms based on this approach have good finite sample behavior.

2015

pdf bib
Canonical Context-Free Grammars and Strong Learning: Two Approaches
Alexander Clark
Proceedings of the 14th Meeting on the Mathematics of Language (MoL 2015)

pdf bib
Unsupervised Prediction of Acceptability Judgements
Jey Han Lau | Alexander Clark | Shalom Lappin
Proceedings of the 53rd Annual Meeting of the Association for Computational Linguistics and the 7th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)

2014

pdf bib
Distributional Learning as a Theory of Language Acquisition
Alexander Clark
Proceedings of the 5th Workshop on Cognitive Aspects of Computational Language Learning (CogACLL)

2013

pdf bib
Statistical Representation of Grammaticality Judgements: the Limits of N-Gram Models
Alexander Clark | Gianluca Giorgolo | Shalom Lappin
Proceedings of the Fourth Annual Workshop on Cognitive Modeling and Computational Linguistics (CMCL)

2010

pdf bib
Efficient, Correct, Unsupervised Learning for Context-Sensitive Languages
Alexander Clark
Proceedings of the Fourteenth Conference on Computational Natural Language Learning

2009

pdf bib
Another Look at Indirect Negative Evidence
Alexander Clark | Shalom Lappin
Proceedings of the EACL 2009 Workshop on Cognitive Aspects of Computational Language Acquisition

pdf bib
A Note on Contextual Binary Feature Grammars
Alexander Clark | Rémi Eyraud | Amaury Habrard
Proceedings of the EACL 2009 Workshop on Computational Linguistic Aspects of Grammatical Inference

2008

pdf bib
CoNLL 2008: Proceedings of the Twelfth Conference on Computational Natural Language Learning
Alexander Clark | Kristina Toutanova
CoNLL 2008: Proceedings of the Twelfth Conference on Computational Natural Language Learning

pdf bib
A Comparative Study of Mixture Models for Automatic Topic Segmentation of Multiparty Dialogues
Maria Georgescul | Alexander Clark | Susan Armstrong
Proceedings of the Third International Joint Conference on Natural Language Processing: Volume-II

2006

pdf bib
An Analysis of Quantitative Aspects in the Evaluation of Thematic Segmentation Algorithms
Maria Georgescul | Alexander Clark | Susan Armstrong
Proceedings of the 7th SIGdial Workshop on Discourse and Dialogue

pdf bib
Word Distributions for Thematic Segmentation in a Support Vector Machine Approach
Maria Georgescul | Alexander Clark | Susan Armstrong
Proceedings of the Tenth Conference on Computational Natural Language Learning (CoNLL-X)

pdf bib
Learning Auxiliary Fronting with Grammatical Inference
Alexander Clark | Rémi Eyraud
Proceedings of the Tenth Conference on Computational Natural Language Learning (CoNLL-X)

2005

pdf bib
Proceedings of the Workshop on Psychocomputational Models of Human Language Acquisition
William Gregory Sakas | Alexander Clark | Royal Holloway | James Cussens | Aris Xanthos
Proceedings of the Workshop on Psychocomputational Models of Human Language Acquisition

2004

pdf bib
Grammatical Inference and First Language Acquisition
Alexander Clark
Proceedings of the Workshop on Psycho-Computational Models of Human Language Acquisition

pdf bib
Multi-level Dialogue Act Tags
Alexander Clark | Andrei Popescu-Belis
Proceedings of the 5th SIGdial Workshop on Discourse and Dialogue at HLT-NAACL 2004

pdf bib
Building and Using a Corpus of Shallow Dialogue Annotated Meetings
Andrei Popescu-Belis | Maria Georgescul | Alexander Clark | Susan Armstrong
Proceedings of the Fourth International Conference on Language Resources and Evaluation (LREC’04)

pdf bib
Partially Distribution-Free Learning of Regular Languages from Positive Samples
Alexander Clark | Franck Thollard
COLING 2004: Proceedings of the 20th International Conference on Computational Linguistics

2003

pdf bib
Combining Distributional and Morphological Information for Part of Speech Induction
Alexander Clark
10th Conference of the European Chapter of the Association for Computational Linguistics

2002

pdf bib
Memory-Based Learning of Morphology with Stochastic Transducers
Alexander Clark
Proceedings of the 40th Annual Meeting of the Association for Computational Linguistics

2001

pdf bib
Unsupervised induction of stochastic context-free grammars using distributional clustering
Alexander Clark
Proceedings of the ACL 2001 Workshop on Computational Natural Language Learning (ConLL)

2000

pdf bib
Inducing Syntactic Categories by Context Distribution Clustering
Alexander Clark
Fourth Conference on Computational Natural Language Learning and the Second Learning Language in Logic Workshop