Design of Concrete Diagrams -- Aesthetics and Ordering in Stacked Area Charts -- Interactive, Orthogonal Hyperedge Routing in Schematic Diagrams Assisted by Layout Automatisms -- Evidence of Chunking in A Simple Drawing Task -- Theory of Diagrams -- Considerations in Representation Selection for Problem Solving: a Review -- Diagrams as part of Physical Theories: A Representational Conception -- Diagrams and Mathematics -- Beyond counting: Measuring diagram intensity in mathematical research papers -- On the relationship between geometric objects and figures in Euclidean geometry -- What Diagrams Are Considered Useful for Solving Mathematical Word Problems in Japan? -- Diagrams and Logic -- The search for symmetry in Hohfeldian modalities -- Wittgenstein's Picture-Investigations -- What kind of opposition-forming operator is privation? -- Presenting Basic Graph Logic -- Schopenhauer's Partition Diagrams and Logical Geometry -- Revisiting Peirce's rules of transformationfor Euler-Venn diagrams -- Tractarian Notations -- Equivalence proof for intuitionistic existential Alpha graphs -- Aaron Schuyler: the missing link between Euler and Venn diagrams? -- Validity as choiceless unification -- Truth Tables without Truth Values: On 4.27 and 4.42 of Wittgenstein's Tractatus -- Combining and relating Aristotelian diagrams -- Residuation in Peirce's Existential Graphs -- On identity in Peirce's Beta Graphs -- Peirce's Diagrammatic Solutions to 'Peirce's Puzzle' -- What are rules for? A Carroll-Peirce comparison -- A Diagrammatic Representation of Hegel's Science of Logic -- Jin Yuelin's Simplification of Venn Diagrams -- Venn Diagrams with "Most": A Natural Logic Approach -- New Representation Systems -- New Representations of Modal Functions -- Diagramming Incomplete and Imprecise Temporal Information -- Comics and Diagrams: An Introductory Overview -- Analysis of Diagrams -- Image Schemas in Diagrammatic Reasoning: the Case of Hasse Diagrams -- Through the eyes of an archeologist: studying the role of prior knowledge in learning with diagrams -- The fall and rise of resemblance diagrams -- The Science of Seeing Science: Examining the Visuality Hypothesis -- Can humans and machines classify photographs as depicting negation? -- The Presence of Diagrams and Problems Requiring Diagram Construction: Comparing Mathematical Word Problems in Japanese and Canadian Textbooks -- Diagrams and Computation -- Extracting Interactive Actor-Based Data ow Models from Legacy C Code -- Visualising Lattices with Tabular Diagrams -- Understanding scholarly neural network system diagrams through application of VisDNA -- A universal grammar for parsing visualization types { using visually enforced combination rules -- Visualizing Program State as a Clustered Graph for Learning Programming -- Dynamic Flowcharts for Enhancing Learners' Understanding of the Control Flow during Programming Learning -- Cognitive Analysis -- Cognitive Properties of Representations: A Framework -- Intentional Diagram Design: Using Gestalt Perceptual Grouping in Cladograms to Tackle Students' Misconceptions -- Cognitive Style's Effects on User Task Performance in Network Visualisations -- Concentrating Competency Pro le Data Into Cognitive Map of Knowledge Diagnosis -- Diagrams as Structural Tools -- Interactivity in Linear Diagrams -- Diagrammatic Representations of Uncertainty in Meteorological Forecasting -- Structuralist analysis for neural network system diagrams -- Modeling Multimodal Interactions and Feedback for Embodied Geovisualization -- Formal Diagrams -- On the Cognitive Potential of Derivative Meaning in Aristotelian Diagrams -- Number and quality of diagrams in scholarly publications is associated with number of citations -- How can numerals be iconic? More varieties of iconicity -- Natural Deduction for Intuitionistic Euler-Venn Diagrams -- Understanding Thought Processes -- Observing Strategies of Drawing Data Representations -- Diagrams in Essays:Exploring the Kinds of Diagrams Students Generate and How Well They Work -- How can we statistically analyze the achievement of diagrammatic literacy from high school regular tests?.

This book constitutes the refereed proceedings of the 12th International Conference on the Theory and Application of Diagrams, Diagrams 2021, held virtually in September 2021. The 16 full papers and 25 short papers presented together with 16 posters were carefully reviewed and selected from 94 submissions. The papers are organized in the following topical sections: design of concrete diagrams; theory of diagrams; diagrams and mathematics; diagrams and logic; new representation systems; analysis of diagrams; diagrams and computation; cognitive analysis; diagrams as structural tools; formal diagrams; and understanding thought processes. 10 chapters are available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.