| 1991 | A Formal Basis for Analogical Reasoning. Charles Dierbach, Daniel L. Chester |
| 1991 | A Formal Theory of Spatial Reasoning. Stephen G. Kaufman |
| 1991 | A General Framework for Modal Deduction. Alan M. Frisch, Richard B. Scherl |
| 1991 | A Metalinguistic Treatment of Epistemic Contexts. Paul Schweizer |
| 1991 | A New Formalisation of Subsumption in Frame-Based Representation Systems. Jacqueline Castaing |
| 1991 | A Nonmonotonic Assumption-Based TMS Using Stable Bases. William L. Rodi, Stephen G. Pimentel |
| 1991 | A Temporal Probability Logic for Representing Actions. Peter Haddawy |
| 1991 | A Theory of Inferred Causation. Judea Pearl, Thomas Verma |
| 1991 | Assertional Default Theories: A Semantical View. Torsten Schaub |
| 1991 | Belief Revision and Default Reasoning: Syntax-Based Approaches. Bernhard Nebel |
| 1991 | Beyond Negation as Failure. Hector Geffner |
| 1991 | Clustering Temporal Intervals To Generate Reference Hierarchies. William S. Davis, James R. Carnes |
| 1991 | Completable Representations of Constraint Satisfaction Problems. Eugene C. Freuder |
| 1991 | Computational Considerations in Reasoning about Action. Matthew L. Ginsberg |
| 1991 | Conditional Objects and Non-Monontonic Reasoning. Didier Dubois, Henri Prade |
| 1991 | Credulous vs. Sceptical Semantics for Ordered Logic Programs. Dov M. Gabbay, Els Laenens, Dirk Vermeir |
| 1991 | Default Logic Revisited. James P. Delgrande, W. Ken Jackson |
| 1991 | Disjective Defaults. Michael Gelfond, Halina Przymusinska, Vladimir Lifschitz, Miroslaw Truszczynski |
| 1991 | Generalizing Atoms in Constraint Logic. C. David Page Jr., Alan M. Frisch |
| 1991 | Generalizing Prioritization. Benjamin N. Grosof |
| 1991 | Immortal: A Model-Based Belief Revision System. Seng-Cho Timothy Chou, Marianne Winslett |
| 1991 | Implemented Knowledge Representation and Reasoning Systems: An Endangered Species? Charles Rich |
| 1991 | Integrating Efficient Model-Learning and Problem-Solving Algorithms in Permutation Environments. Prasad Chalasani, Oren Etzioni, John Mount |
| 1991 | Knowledge Interchange Format. Michael R. Genesereth |
| 1991 | Knowledge Sharing: A Feasible Dream. Giuseppe Attardi |
| 1991 | Meta-Reasoning in Executable Temporal Logic. Howard Barringer, Michael Fisher, Dov M. Gabbay, Anthony Hunter |
| 1991 | Metalogic for Knowledge Representation. Antonio Brogi, Franco Turini |
| 1991 | Modal Nonmonotonic Logics: Ranges, Characterization, Computation. V. Wiktor Marek, Grigori F. Shvarts, Miroslaw Truszczynski |
| 1991 | Model Checking vs. Theorem Proving: A Manifesto. Joseph Y. Halpern, Moshe Y. Vardi |
| 1991 | Modeling Rational Agents within a BDI-Architecture. Anand S. Rao, Michael P. Georgeff |
| 1991 | Naming and Identity in a Multi-Agent Epistemic Logic. Adam J. Grove, Joseph Y. Halpern |
| 1991 | Nonmonotonic Inferences Based on Expectations: A Preliminary Report. Peter Gärdenfors |
| 1991 | Nonmonotonic Inferences in Neural Networks. Christian Balkenius, Peter Gärdenfors |
| 1991 | On the Difference between Updating a Knowledge Base and Revising It. Hirofumi Katsuno, Alberto O. Mendelzon |
| 1991 | On the Relation between Explicit and Implicit Belief. Gerhard Lakemeyer |
| 1991 | Panel: Achieving Large Scale Knowledge Sharing. William Mark |
| 1991 | Partial Programs. Michael R. Genesereth, Jane Yung-jen Hsu |
| 1991 | Plan-Based Terminological Reasoning. Premkumar T. Devanbu, Diane J. Litman |
| 1991 | Planning as Temporal Reasoning. James F. Allen |
| 1991 | Pragmatic Logics. John Bell |
| 1991 | Probably Approximately Optimal Derivation Strategies. Russell Greiner, Pekka Orponen |
| 1991 | Proceedings of the 2nd International Conference on Principles of Knowledge Representation and Reasoning (KR'91). Cambridge, MA, USA, April 22-25, 1991. James F. Allen, Richard Fikes, Erik Sandewall |
| 1991 | Qualifying Number Restrictions in Concept Languages. Bernhard Hollunder, Franz Baader |
| 1991 | Qualitative Intercausal Relations, or Explaining "Explaining Away". Michael P. Wellman, Max Henrion |
| 1991 | Qualitative Simulation with Multivariate Constraints. Michael P. Wellman |
| 1991 | Rational Belief Revision. Jon Doyle |
| 1991 | Reflections about Reflection. Giuseppe Attardi, Maria Simi |
| 1991 | S4 as the Conditional Logic of Nonmonotonicity. Philippe Lamarre |
| 1991 | Skeptical Reason Maintenance is Tractable. Cees Witteveen |
| 1991 | Temporal Reasoning and Narrative Conventions. Jonathan Amsterdam |
| 1991 | The Completeness of DRAT, A Technique for Automatic Design of Satisfiability Procedures. Jeffrey Van Baalen |
| 1991 | The Complexity of Concept Languages. Francesco M. Donini, Maurizio Lenzerini, Daniele Nardi, Werner Nutt |
| 1991 | The Computational Value of Nonmonotonic Reasoning. Matthew L. Ginsberg |
| 1991 | The Feasibility of Defeat in Defeasible Reasoning. Gerard Vreeswijk |
| 1991 | The Logic of Epistemic Inconsistency. Tarcisio H. C. Pequeno, Arthur Buchsbaum |
| 1991 | The Monotonic Abduction Problem: A Functional Characterization on the Edge of Tractability. Tom Bylander |
| 1991 | The Ontology and Representation of Situations. Robert Wilensky |
| 1991 | The Role of Common Ontology in Achieving Sharable, Reusable Knowledge Bases. Thomas R. Gruber |
| 1991 | The Utility of Consistency-Based Diagnostic Techniques. Gregory M. Provan, David L. Poole |
| 1991 | Toward a Metatheory of Action. Vladimir Lifschitz |
| 1991 | Universal Attachment: An Integration Method for Logic Hybrids. Karen L. Myers |
| 1991 | Updates and Counterfactuals. Gösta Grahne |