Invited Lectures -- Methods of Conceptual Knowledge Processing -- An Enumeration Problem in Ordered Sets Leads to Possible Benchmarks for Run-Time Prediction Algorithms -- Attribute Implications in a Fuzzy Setting -- The Assessment of Knowledge, in Theory and in Practice -- Regular Papers -- The Basic Theorem on Preconcept Lattices -- The Tensor Product as a Lattice of Regular Galois Connections -- Two Instances of Peirce’s Reduction Thesis -- Very Fast Instances for Concept Generation -- Negation, Opposition, and Possibility in Logical Concept Analysis -- A Note on Negation: A PCS-Completion of Semilattices -- Towards a Generalisation of Formal Concept Analysis for Data Mining Purposes -- Interactive Association Rules Discovery -- About the Family of Closure Systems Preserving Non-unit Implications in the Guigues-Duquenne Base -- Spatial Indexing for Scalability in FCA -- Homograph Disambiguation Using Formal Concept Analysis -- Using Concept Lattices to Uncover Causal Dependencies in Software -- An FCA Interpretation of Relation Algebra -- Spring-Based Lattice Drawing Highlighting Conceptual Similarity -- Characterizing Planar Lattices Using Left-Relations -- Automated Layout of Small Lattices Using Layer Diagrams -- Counting Pseudo-intents and #P-completeness.