Lenhart K. Schubert
Professor
Computer Science Department
Rochester, NY 14627-0226
Email: lastname AT cs DOT rochester DOT edu
Fax: (585) 273-4556
Ph.D. (1970) University of Toronto. Assistant Professor
(73-77), Associate Professor (77-84), Professor (84-88); University of
Alberta. Professor (88-present), University of Rochester. I am also a
member of the Center
for Language Sciences (CLS) and the Center
for Computation and the Brain.
My research interests center around language, knowledge
representation, inference and planning. These interests are tied
together by the general goal of developing agents with common sense
and the ability to converse and acquire knowledge through language.
Some specific topics my students and I have worked on include
- very expressive, language-like logics to capture the content of
ordinary language and commonsense reasoning as directly as possible;
the most recent is called Episodic Logic;
- semantics of events/situations, tense/aspect, reference, affixes,
mass terms, generic sentences, belief, questions, vagueness;
- efficient, specialized inference techniques for taxonomies,
part-structure, temporal relations, and other classes of relations
that pervade commonsense knowledge and are handled effortlessly
by people;
- methods of organizing knowledge and inference so that a
general-purpose reasoner will easily locate knowledge relevant to
a particular task (even for a very large knowledge base), and will
smoothly integrate general and specialized inference techniques;
- strategies for human-like, error-tolerant natural language parsing
and disambiguation, and for mapping syntactic structure to a
representation of the underlying meaning (allowing for context);
- development of implementations of the above knowledge representations
and inference techniques; the latest is called
EPILOG, and supports
the Episodic Logic knowledge representation and integrates general
and specialized inference mechanisms;
- Deriving general
world knowledge from texts and taxonomies, as an attack on the
"knowledge acquisition bottleneck" in AI; the current system is
called KNEXT
(KNowledge EXtraction from Text).
- reasoning about plans and actions, in support of both language
understanding (e.g., conversation planning and inferring the
goals and plans of story characters) and domain reasoning
(e.g., formulating plans of action in a transportation domain);
automatically discovering invariants in planning domains -- see
the DISCOPLAN
system; solving the Frame Problem using "explanation closure".
Office hours, Spring 2008:
Tuesday and Thursday, 1:00-2:00 (tentative)
Current and recent courses:
CSC 191/291 (Topics in Computer Science): Machines and Consciousness
CSC 244/444: Logical Foundations of Artificial
Intelligence
CSC 247/447: Natural Language Processing
CSC 280: Computer Models and Limitations
CSC 242: Artificial Intelligence
Present research collaborators:
James Allen: Dialogue processing, deep understanding
Greg Carlson:
(Linguistics) Acquiring & bootstrapping general knowledge from texts
Benjamin Van Durme Generic knowledge acquisition
Daphne Liu Self-motivated cognitive agents
Jonathan Gordon: Knowledge extraction
Adam Purtee: Pattern transduction for NLP
Carolyn Keenan Acquiring lexical meaning postulates via VerbNet
Shuopeng Deng Acquiring lexical meaning postulates via WordNet
Matt Overlan
Acquiring lexical meaning postulates via VerbNet
Alfonso Gerevini (U. Brescia):
Efficient domain-independent planning
Some past research collaborators:
Adina Rubinoff (now at Factset, Norwalk, CT),
Acquiring lexical meaning postulates via VerbNet
Fabrizio Morbini (Ph.D. 2009, now at the Institute for Creative Technologies, Playa Vista, CA).
Ting Qian: (now a BCS PhD candidate)
Class attribute extraction, lexical semantics
Henry Kyburg, Jr.: http://www.cs.rochester.edu/dept/news/kyburg_obituary.shtml
Proshanto Mukherji: (Ph.D. 2006, now an Associate at Fish & Richardson in Boston, after earning a JD at Harvard
Law School):
Discovering Laws as Anomalies in Logical Worlds
Tom Weingarten (Now CTO at Delve News, New York, after a Ph.D. in Computational Biology at NYU):
as URCS undergraduate worked on "Using pulse train to compute probabilities
in Bayesian networks
David Ahn: (Ph.D. 2004, now a Natural Language Scientist at Powerset (LinkedIn):
Semantics/pragmatics of adverbially quantified sentences
Teresa Zollo: (Ph.D. 2003, now at Ithaca College --
new URL):
Recovery from speech recognition errors
Matthew Tong:
(B.Sc. 2003, now a doctoral student in
Computer Science at UCSD):
Mining general world knowledge from texts
Amon Seagull (Ph.D. 2000, now at Nova Southeastern
University, Florida, new URL):
Well-foundedness and reliability in natural language parsing
Aaron Kaplan:, (Ph.D. 2000, now lead software engineer
at NewsCred, New York, after 10 years at XRCE, Grenoble, France)
A computational model of belief
Mark Core (Ph.D. 2000, now at the Institute for Creative Technologies, Playa Vista, CA):
Dialog parsing: From speech repairs to speech acts
Marc Light (Ph.D. 1995, now senior scientist at WindLogics, St. Paul):
Morphological cues for lexical semantics
Massimo Poesio (Ph.D. 1994, now at U. of Essex, U.K.):
Assigning semantic scope to operators in dialogues
Chung Hee Hwang (Ph.D. 1992, now at Motorola's Intelligent Systems Lab in
Phoenix, AZ):
A logical approach to narrative understanding,
Episodic Logic
Alice Kyburg (Ph.D. 1994, now at U. Wisconsin at Oshkosh):
Pragmatic and semantic accounts of vagueness
Stephanie Schaeffer (M.S. 1988, systems prog., 1988-92, U. Alberta):
Temporal reasoning, hybrid reasoning, EPILOG development
Jeffry Pelletier (U. Alberta):
Semantic interpretation, semantics of mass terms and generics
Fahiem Bacchus (Ph.D. 1988, now at U. Toronto):
Representing and reasoning about probabilistic knowledge
Caoan Wang (Ph.D. 1988, now at Memorial U. of Newfoundland):
Computational geometry
Professional activities and awards
KR'98 program co-chair
ACL'93 program chair
CSCSI'80 program chair
ACM Trans. on Computational Logic editorial board (2007-pres)
JAIR editorial board (1996-1999)
Computational Intelligence editorial board (1985-2003)
Computational Linguistics editorial board (1983-5)
Fellow of the AAAI (elected in 1993 for "fundamental contributions in NLP,
esp. in the formalization, representation, and practical implementation
of non-first order concepts")
Alexander von Humboldt Fellow (1978-9)
Associate of the Canadian Institute for Advanced Research (1985-88)
Outstanding Contribution award for the KR'89 paper (with C.H. Hwang),
"An episodic knowledge representation for narrative texts"
Selected Publications
(underlined titles provide pdf files in most cases)
- L.K. Schubert, "NLog-like
inference and commonsense reasoning", Dept. of Computer Science,
University of Rochester, Oct. 2012. To appear in C. Condoravdi & A. Zaenen,
(eds.) Semantics for Textual Inference, CSLI 2013.
- A. Purtee and L.K. Schubert, "TTT:
A tree transduction language for syntactic and semantic processing",
EACL 2012 Workshop on Applications of Tree Automata Techniques in Natural
Language Processing (ATANLP 2012), Avignon, France, Apr. 24, 2012.
- L.K. Schubert, J. Gordon, K. Stratos, and A. Rubinoff,
"Towards adequate knowledge and natural inference",
in Proc. of AAAI Fall Symposium on Advances in Cognitive Systems (ACS '11),
Arlington, VA, Nov. 4-6, 2011.
- K. Stratos, L.K. Schubert, & J. Gordon,
"Episodic Logic:
Natural Logic + reasoning", Int. Conf. on Knowledge Engineering and
Ontology Development, (KEOD'11), Oct 26-29, Paris, 2011.
- L.K. Schubert, B. Van Durme, and M. Bazrafshan,
"Entailment inference in a natural logic-like
general reasoner", Common Sense Knowledge Symposium (CSK-10),
AAAI 2010 Fall Symposium Series, Arlington, VA, November 11-13, 2010.
- Daphne Liu and L.K. Schubert,
"Combining
self-motivation with logical planning and inference in a reward-seeking
agent", poster paper, Proc. of the Int. Conf. on Agents and Artificial
Intelligence (ICAART 2010), vol. 2 (INSTICC Press), Valencia, Spain,
Jan. 22-24, 2010, pp. 257-263.
- Jonathan Gordon and Lenhart Schubert,
"Quantificational sharpening
of commonsense knowledge", Proc. of the AAAI Fall Symposium on Commonsense
Knowledge, Arlington, VA, Nov. 11-13, 2010.
- L.K. Schubert,
"From generic
sentences to scripts", IJCAI'09 Workshop W22, Logic and the Simulation
of Interaction and Reasoning (LSIR 2), Pasadena, CA, July 12, 2009.
- F. Morbini and L.K. Schubert,
"Evaluation of
Epilog: A reasoner for Episodic Logic", Commonsense'09, June 1-3,
2009, Toronto, Canada. Also available at http://commonsensereasoning.org/2009/papers.html
- L.K. Schubert,
"Language Understanding
as Recognition and Transduction of Numerous Overlaid Patterns",
AAAI Spring Symposium on Learning by Reading and Learning to Read,
Mar 23-25, 2009, Stanford, pp. 94-96.
- D. Liu and L.K. Schubert,
"Incorporating
planning and reasoning into a self-motivated, communicative agent",
The 2nd Conf. on Artificial General Intelligence (AGI-09), Arlington,
VA, March 6-9, 2009, pp. 108-113.
- B. Van Durme, P. Michalak, and L.K. Schubert,
"Deriving
generalized knowledge from corpora using WordNet abstraction",
12th Conf. of the European Chapter of the Assoc. for Computational
Linguistics (EACL-09), Mar. 30 - Apr. 3, 2009, Athens, Greece.
- L.K. Schubert and B. Van Durme,
"Open
extraction of general knowledge through compositional semantics",
Notebook of the NSF Symposium on Semantic Knowledge Discovery,
Organization and Use, New York University, Nov. 14-15, 2008.
- F. Morbini and L.K. Schubert,
"Metareasoning as an integral
part of commonsense and autocognitive reasoning", AAAI'08
Workshop on Metareasoning, July 13-14, 2008, Chicago, pp 155-162.
- Benjamin Van Durme, Ting Qian and Lenhart K. Schubert,
"Class-driven attribute
extraction", COLING'08, Aug. 18-22, 2008, Manchester, UK.
- Benjamin Van Durme and Lenhart K. Schubert,
"Open knowledge extraction
using compositional language processing", Symposium on Semantics
in Systems for Text Processing (STEP 2008), September 22-24, 2008 -
Venice, Italy.
- F. Morbini and L.K. Schubert,
"Towards
realistic autocognitive inference", Logical Formalizations
of Commonsense Reasoning, Papers from the AAAI Spring Symposium,
Tech. Rep. SS-07-05, AAAI Press, Menlo Park, CA, March 26-28,
Stanford, pp. 114-118, 2007.
- L.K. Schubert, "Implicit Skolemization:
Efficient reference to dependent entities", Research on
Language and Computation 5, April 2007, (special volume on
Binding Theory, ed. by Alastair Butler, Ed Keenan, Jason Mattausch
and Ken Shan), pp. 69-86. Pre-publication
version (differing only in format).
- L.K. Schubert,
"Turing's
dream and the knowledge challenge", 21st Nat. Conf. on
Artificial Intelligence (AAAI'2006), July 16-20, 2006, Boston,
MA, AAAI Press, Menlo Park, CA, pp. 1534-8.
- L.K. Schubert,
"Some
KR&R requirements for self-awareness", 2005 AAAI Spring Symposium on
Metacognition in Computation, Stanford University, March 21-23, 2005.
- L.K. Schubert, ``A new characterization of
probabilities in Bayesian networks", Uncertainty in AI: Proc.
of the 20th Conference (UAI 2004), Banff, Canada, July 7-11.
Extended version forthcoming as tech. rep., Dept. of Comp. Sci.,
Univ. of Rochester, Rochester, NY 14627-0226.
- L.K. Schubert and M.H. Tong, ``Extracting
and evaluating general world knowledge from the Brown corpus",
Proc. of the HLT/NAACL 2003 Workshop on Text Meaning, May 31,
Edmonton, Alberta, Canada. (postscript)
- L.K. Schubert, ``Can we
derive general world knowledge from texts?", M. Marcus (ed.),
Proc. of the 2nd Int. Conf. on Human Language Technology
Research (HLT 2002), March 24-27, San Diego, CA, pp. 94-97.
(postscript)
- A.N. Kaplan and L.K. Schubert,
"Measuring and improving the quality of world knowledge extracted from WordNet",
Tech. Rep. 751, Dept. of Computer Science, Univ. of Rochester, May 2001.
- L.K. Schubert, "The situations we
talk about", in J. Minker (ed.), Logic-Based Artificial
Intelligence,
Kluwer,
Dortrecht, 2000, 407-439. (postscript)
- A.N. Kaplan and L.K. Schubert,
"A
computational model of belief", Artificial Intelligence 120(1),
June 2000, 119-160.
- A. Gerevini and L.K. Schubert,
"Discovering state constraints
in DISCOPLAN: Some new results", Proc. of the 17th Nat. Conf. on
Artificial Intelligence (AAAI'2000), July 30-August 3, 2000,
Austin, Texas.
- L.K. Schubert and C.H. Hwang,
"Episodic Logic meets Little Red
Riding Hood: A comprehensive, natural representation for language
understanding", in L. Iwanska and S.C. Shapiro (eds.), Natural
Language Processing and Knowledge Representation: Language for Knowledge
and Knowledge for Language, MIT/AAAI Press, Menlo Park, CA, and
Cambridge, MA, 2000, 111-174. See
MIT Press website for the book.
- L.K. Schubert, "Dynamic
Skolemization", in H. Bunt and R. Muskens (eds.),
Computing Meaning, vol. 1, Studies in Linguistics & Philosophy
Series, Kluwer Academic Press, Dortrecht (also Boston, London), 1999,
219-253.
- A. Gerevini and L.K. Schubert,
"Inferring state constraints for domain-independent planning",
Proc. of the 15th Nat. Conf. on Artificial Intelligence (AAAI-98),
July 26-30, Madison, WI, 1998.
- M.G. Core and L.K. Schubert, "Implementing parser metarules that handle
speech repairs and other disruptions", 11th Int. FLAIRS Conference,
Special Track on Natural Language Processing and Human-Computer
Interaction, Sundial Beach, Florida, May 17-20, 1998.
- M.G. Core and L.K. Schubert, "Handling speech repairs and other
disruptions through parser metarules", AAAI Spring Symposium on
Computational Models for Mixed Initiative Interaction, Mar. 24-16,
Stanford U., 1997.
- M. Light and L.K. Schubert, "Knowledge representation for lexical
semantics: Is standard first-order logic enough?", in H. Bunt,
L. Kievit, R. Muskens, and M. Verlinden (eds.), IWCS II: 2nd Int.
Workshop on Computational Semantics, Tilburg University, Netherlands,
Jan. 8-10, 1997.
- A. N. Kaplan and L.K. Schubert, "Simulative inference in a computational
model of belief", in H. Bunt and R. Muskens (eds.), Computational
Semantics, Studies in Linguistics & Philosophy Series, to appear.
Preliminary version in H. Bunt, L. Kievit, R. Muskens, and M. Verlinden
(eds.), IWCS II: Second International Workshop on Computational Semantics,
Tilburg University, Netherlands, Jan. 8-10, 1997. Expanded version in
Tech. Rep. 636, Dept. of Computer Science, U. Rochester, Rochester, NY
14627-0226, October 1997.
- L.K. Schubert, "Framing the donkey: Towards a unification of semantic
representations with knowledge representations", AAAI Fall Symp. on
Knowledge Representation Systems based on Natural Language, Nov. 9-11,
Cambridge, MA, 1996.
- A. Gerevini and L.K. Schubert, "Accelerating partial-order planners:
Some techniques for effective search control and pruning", J. of
Artificial Intelligence Research 5, pp. 95-137, Sept. 1996.
- D. Traum, L.K. Schubert, M. Poesio, N. Martin, M. Light, C.H. Hwang,
P. Heeman, G. Ferguson, J.F. Allen, "Knowledge representation in the
TRAINS-93 conversation system", Int. J. of Expert Systems 9(1),
special issue on Knowledge Representation and Inference for Natural
Language Processing, pp. 173-223, 1996.
- A. Gerevini and L.K. Schubert, "Computing parameter domains
as an aid to planning", Proc. of the 3rd Int. Conf. on Artif. Intell.
Planning Systems (AIPS-96) (B. Drabble, ed.), May 29-31, Edinburgh,
The AAAI Press, Menlo Park, CA, pp. 94-101., 1996.
- L.K. Schubert and A. Gerevini, "Accelerating partial order planners
by improving plan and goal choices", Proc. of the 7th Int. Conf.
on Tools with AI (ICTAI'95), Nov. 5-8, Herndon, VA, 1995, pp. 442-450.
- Gerevini, A. and L. K. Schubert. ``Efficient algorithms for
qualitative reasoning about time", Artificial Intelligence 74(2),
pp. 207-248, 1995.
- J.F. Allen, L. K. Schubert, G. M. Ferguson, P. A. Heeman,
C. H. Hwang, T. Kato, M. Light, N. G. Martin, B. W. Miller,
M. Poesio, and D.R. Traum. "The TRAINS project: A case study in
building a conversational planning agent," J. Experimental and
Theoretical Artificial Intelligence 7, 7-48, 1995.
- C.H. Hwang and L. K. Schubert, "Interpreting
tense, aspect, and time adverbials: a compositional, unified
approach'', in D.M. Gabbay and H.J. Ohlbach (eds.), Proc. of
the 1st Int. Conf. on Temporal Logic, July 11-14, Bonn, Germany,
Springer-Verlag, pp. 238-264, 1994.
- L.K. Schubert, "Explanation
closure, action closure, and the Sandewall test suite for reasoning
about change", J. of Logic and Computation 4(5), Special
Issue on Actions and Processes, pp. 679-799, 1994. Reprinted with
minor changes in H.J. Levesque and F. Pirri (eds.), Logical
Foundations for Cognitive Agents: Contributions in Honor of Ray
Reiter, Springer, Berlin, 1999, pp. 325-351.
- A. Gerevini, L.K. Schubert, and S. Schaeffer. "The temporal
reasoning tools TimeGraph-I-II.'' Proc. of the 6th IEEE Int. Conf.
on Tools with Artificial Intelligence, Nov. 6-9, New Orleans,
Louisiana, 1994.
- C.H. Hwang and L.K. Schubert, "Meeting the interlocking needs
of LF-computation, deindexing, and inference: An organic approach
to general NLU.'' In Proc. 13th Int. Joint Conf. on Artificial
Intelligence, August, 1993.
- C.H. Hwang and L.K. Schubert, "Episodic
Logic: A situational logic for natural language processing,"
In P. Aczel, D. Israel, Y. Katagiri, and S. Peters (eds.),
Situation Theory and its Applications 3 (STA-3), CSLI,
307-452, 1993.
- L.K. Schubert,
"Monotonic solution of the frame problem in the situation calculus:
An efficient method for worlds with fully specified actions,"
in H. Kyburg, R. Loui and G. Carlson (eds.), Knowledge Representation
and Defeasible Reasoning, Kluwer, Dortrecht, pp. 23-67, 1990.
(A pdf
version is also available.)
- S.A. Miller and L.K. Schubert,
"Time revisited", Computational Intelligence 6(2), 108-118, 1990.
(A lower-resolution scanned pdf
version is also available.)
- F.J. Pelletier and L.K. Schubert,
"Mass Expressions", in D. Gabbay & F. Guenthner (eds.), Handbook
of Philosophical Logic, Vol. 4, Reidel, Dortrecht, 327-407, 1989.
[Expanded version reprinted in second edition [2003] of this Handbook,
volume 10, pp. 265-350.]
- L.K. Schubert and F.J. Pelletier,
"Generically speaking, or,
using discourse representation theory to interpret generics",
in G. Chierchia, B. Partee, R. Turner (eds.), Property Theory, Type
Theory, and Semantics, Vol. II, Kluwer, 193-268, 1989. [scanned:
very large file]
- L.K. Schubert and F.J. Pelletier,
"Problems in
Representing the Logical Form of Generics, Bare Plurals, and Mass Terms",
in E. Lepore (ed.), New Directions in Semantics, Academic Press,
387-453, 1987.
- L.K. Schubert, "Are there
preference trade-offs in attachment decisions?", Proc. of the 5th Nat.
Conf. on Artificial Intelligence (AAAI-86), August 11-15, Philadelphia,
PA, pp. 601-605, 1986.
- F.J. Pelletier and L.K. Schubert,
Two theories for computing the logical form of mass expressions", Proc.
of the 10th Int. Conf. On Computational Linguistics (COLING-84), July 2-6,
Stanford Univ., Stanford, CA, 108-111, 1984.
- L.K. Schubert,
"On parsing preferences", Proc. of the 10th Int. Conf. On
Computational Linguistics (COLING-84), July 2-6, Stanford Univ.,
Stanford, CA, 247-250, 1984.
- L.K. Schubert and F.J. Pelletier,
From English to logic: Context-free computation of 'conventional' logical
translations", Am. J. of Computational Linguistics 8 [now
Computational Linguistics], 26-44, 1982. (Reprinted, with corrections,
in B. Grosz, K. Spark-Jones, B. Webber (eds.), Readings in Natural
Language Processing, Morgan Kaufmann, Los Gatos, CA, 293-311, 1986.)
- D.T. Johnson and L.K. Schubert,
"A planning control strategy that
allows for the cost of planning, Proc. of the 6th European Meeting
on Cybernetics and Systems, Univ. of Vienna, Vienna, Austria, Apr. 13-16,
1982.