Atsushi Shimojima

Why are diagrams sometimes so useful, while other times unhelpful and even misguiding? There are systematic reasons for this. Drawing on modern research in logic, Artificial Intelligence, cognitive psychology, and graphic design, "Semantic Properties of Diagrams and their Cognitive Potentials" shows that diagrams' cognitive functions are rooted in the characteristic ways they carry information about their targets. The analysis leads to an answer for the deeper question of What makes a diagram a diagram?, which is of crucial importance to the foundation of a collective science of diagrams. "

With the rise of the internet and the proliferation of technology to gather and organize data, our era has been defined as "the information age." With the prominence of information as a research concept, there has arisen an increasing appreciation of the intertwined nature of fields such as logic, linguistics, and computer science that answer the questions about information and the ways it can be processed. The many research traditions do not agree about the exact nature of information. By bringing together ideas from diverse perspectives, this book presents the emerging consensus about what a conclusive theory of information should be. The book provides an introduction to the topic, work on the underlying ideas, and technical research that pins down the richer notions of information from a mathematical point of view. The book contains contributions to a general theory of information, while also tackling specific problems from artificial intelligence, formal semantics, cognitive psychology, and the philosophy of mind. There is focus on the dynamics of information flow, and also a consideration of static approaches to information content; both quantitative and qualitative approaches are represented

Semantic studies on diagrammatic notations (Barwise & Etchemendy, ; Shimojima, ; Stenning & Lemon, ) have revealed that the “non-deductive,” “emergent,” or “perceptual” effects of diagrams (Chandrasekaran, Kurup, Banerjee, Josephson, & Winkler, ; Kulpa, ; Larkin & Simon, ; Lindsay, ) are all rooted in the exploitation of spatial constraints on graphical structures. Thus, theoretically, this process is a key factor in inference with diagrams, explaining the frequently observed reduction of inferential load. The purpose of this study was to examine the empirical basis for this theoretical suggestion, focusing on the reality of the constraint-exploitation strategy in actual practices of diagrammatic reasoning. Eye movements were recorded while participants used simple position diagrams to solve three- or four-term transitive inference problems. Our experiments revealed that the participants could exploit spatial constraints on graphical structures even when (a) they were not in the position of actually manipulating diagrams, (b) the semantic rule for the provided diagrams did not match their preferences, and (c) the constraint-exploitation strategy invited a partly adverse effect. These findings indicate that the hypothesized process is in fact robust, with the potential to broadly account for the inferential advantage of diagrams

We define a "representation" as an external object with which we denote another object and present information about it to ourselves or others. All the following objects count as representations in our sense: a set of Japanese declarative sentences describing Mount Fuji, a time table of the Boston subway system, a geometry diagram used to demonstrate the Pythagorean theorem, a state map of the United States, a relief map of a Rocky terrain, a ball-and-stick model of a molecular, and a scale model of the Rockefeller center. ;The dissertation studies how different modes of presenting information exhibit different degrees and kinds of efficacy as an aid for human reasoning. The main hypothesis, which we dub the "Constraint Hypothesis," is that the variance in inferential potentials of different modes of representation is largely attributable to particular ways in which structural constraints on representations match and mismatch with constraints on their targets. The hypothesis is intended to provide a definite perspective for the general study of information representation, which is gradually taking the shape of an independent branch of science. ;As the basis for our analysis, we adopt the mathematical framework of the "qualitative information theory" being developed by Dretske, Barwise, Perry, and Seligman. We analyze several key properties that account for the efficacy of particular modes of representation, including the capacity of providing "free rides" in inference, the property of being over-specific in representing information, and the property of being self-consistent in information content. We also propose an analysis of the conceptual boundary between the "linguistic" modes and the "graphical" modes of representation, and explain some of the important differences in their cognitive potentials. All of these analyses crucially refer to structural constraints on representations and their match and mismatch with constraints on the targets, and hence lend piecemeal yet sturdy supports to our main hypothesis

In order to effectively communicate information, the choice of representation is important. Ideally, a chosen representation will aid readers in making desired inferences. In this paper, we develop the theory of observation: what it means for one statement to be observable from another. Using observability, we give a formal characterization of the observational advantages of one representation of information over another. By considering observational advantages, people will be able to make better informed choices of representations of information. To demonstrate the benefit of observation and observational advantages, we apply these concepts to set theory and Euler diagrams. In particular, we can show that Euler diagrams have significant observational advantages over set theory. This formally justifies Larkin and Simon’s claim that “a diagram is worth ten thousand words”.