The 13th International Conference on Conceptual Structures (ICCS 2005) was held in Kassel, Germany, during July 17 22, 2005. Information about the c- ference can be found atThe title of this year s conference, Common Semantics for Sharing Kno- edge ,waschosentoemphasizeontheonehandtheoverallaimofanyknowledge representationformalism, to support the sharing of knowledge, and on the other hand the importance of a common semantics to avoiddistortion of the meaning. We understand that both aspects are of equal importance for a successful future of the researcharea of conceptual structures. We are thus happy that the papers presentedatICCS2005addressedbothapplicationsandtheoreticalfoundations. Sharing knowledge can also be understood in a separate sense. Thanks to the German Research Foundation, DFG, we were able to invite nine inter- tionally renowned researchers from adjacent research areas. We had stimulating presentationsandlively discussions,with bidirectionalknowledgesharing.Ev- tually the ground can be laid for establishing common semantics between the respective theories. This year, 66 papers were submitted, from which 22 were selected to be included in this volume. In addition, the ?rst nine papers present the invited talks.Wewishtoexpressourappreciationtoalltheauthorsofsubmittedpapers, to the members of the Editorial Board and the Program Committee, and to the external reviewers for making ICCS 2005 a valuable contribution to the knowledge processing research ?eld. Invited Papers.- Patterns for the Pragmatic Web.- Conceptual Graphs for Semantic Web Applications.- Knowledge Representation and Reasoning in (Controlled) Natural Language.- What Is a Concept?.- Applications of Description Logics: State of the Art and Research Challenges.- Methodologies for the Reliable Construction of Ontological Knowledge.- Using Formal Concept Analysis and Information Flow for Modelling and Sharing Common Semantics: Lessons Learnt and Emergent Issues.- On the Need to Bootstrap Ontology Learning with Extraction Grammar Learning.- Conzilla - A Conceptual Interface to the Semantic Web.- Theoretical Foundations.- Variables in Concept Graphs.- Arbitrary Relations in Formal Concept Analysis and Logical Information Systems.- Merge-Based Computation of Minimal Generators.- Representation of Data Contexts and Their Concept Lattices in General Geometric Spaces.- Local Negation in Concept Graphs.- Morphisms in Context.- Contextual Logic and Aristotle's Syllogistic.- States ofDistributed Objects in Conceptual Semantic Systems.- Knowledge Engineering and Tools.- Hierarchical Knowledge Integration Using Layered Conceptual Graphs.- Evaluation of Concept Lattices in a Web-Based Mail Browser.- D-SIFT: A Dynamic Simple Intuitive FCA Tool.- Analyzing Conflicts with Concept-Based Learning.- Querying a Bioinformatic Data Sources Registry with Concept Lattices.- How Formal Concept Lattices Solve a Problem of Ancient Linguistics.- A New Method to Interrogate and Check UML Class Diagrams.- Knowledge Acquisition and Ontologies.- Language Technologies Meet Ontology Acquisition.- Weighted Pseudo-distances for Categorization in Semantic Hierarchies.- Games of Inquiry for Collaborative Concept Structuring.- Toward Cooperatively-Built Knowledge Repositories.- What Has Happened to Ontology.- Enhancing the Initial Requirements Capture of Multi-Agent Systems Through Conceptual Graphs.- Outline of trikonic?* k: Diagrammatic Trichotomic.
