Exploiting the Layout Engine to Assess Diagram Completions

A practicable approach to diagram completion is to first compute model completions on the abstract syntax level. These can be translated to corresponding diagram changes by the layout engine afterwards. Normally, several different model completions are possible though. One way to deal with this issue is to let the user choose among them explicitly, which is already helpful. However, such a choice step is a quite time-consuming interruption of the editing process. We argue that users often are mainly interested in completions that preserve their original diagram as far as possible. This criterion cannot be checked on the abstract syntax level though. In fact, minimal model changes might still result in enormous changes of the original diagram. Therefore, we suggest to use the layout engine in advance for assessing all possible model completions with respect to the diagram changes they eventually cause

Layout Improvement in Diagram Editors by Automatic Ad-hoc Layout

Layout, in the context of diagram editors, is the positioning of diagram components on the screen. Editor users enjoy automatic layout, but they usually like to control the layout at runtime, too. Our pattern-based layout approach allows for automatic and user-controlled layout at the same time: The diagram editor may automatically apply layout patterns to diagram parts based on syntactic rules provided by the editor developer, but editor users may also select diagram parts and then apply layout patterns to them. For instance, user-selected components may be aligned horizontally and remain aligned even after diagram modifications.This paper describes continued work on pattern-based layout. We present automatic ad-hoc layout which combines automatic and user-controlled layout in a new way. While automatic layout is syntax-based and must be specified by the editor developer in advance, automatic ad-hoc layout is solely based on the current diagram layout. Whenever the layout engine detects a situation where a pattern may be applied with no or only small diagram changes, this layout pattern is automatically applied. For instance, if a set of components is almost horizontally aligned on the screen, the horizontal alignment pattern is automatically applied to these components. Such an editor behavior is known from so-called snap lines in commercial diagram editors. Automatic ad-hoc layout generalizes on these manually programmed layout solutions and offers many additional layout features.This paper describes the concept of automatic ad-hoc layout as well as its integration into a diagram editor framework and discusses issues of this new layout approach

Euler Diagram Transformations

Euler diagrams are a visual language which are used for purposes such as the presentation of set-based data or as the basis of visual logical languages which can be utilised for software specification and reasoning. Such Euler diagram reasoning systems tend to be defined at an abstract level, and the concrete level is simply a visualisation of an abstract model, thereby capturing some subset of the usual boolean logic. The visualisation process tends to be divorced from the data transformation process thereby affecting the user's mental map and reducing the effectiveness of the diagrammatic notation. Furthermore, geometric and topological constraints, called wellformedness conditions, are often placed on the concrete diagrams to try to reduce human comprehension errors, and the effects of these conditions are not modelled in these systems. We view Euler diagrams as a type of graph, where the faces that are present are the key features that convey information and we provide transformations at the dual graph level that correspond to transformations of Euler diagrams, both in terms of editing moves and logical reasoning moves. This original approach gives a correspondence between manipulations of diagrams at an abstract level (such as logical reasoning steps, or simply an update of information) and the manipulation at a concrete level. Thus we facilitate the presentation of diagram changes in a manner that preserves the mental map. The approach will facilitate the realisation of reasoning systems at the concrete level; this has the potential to provide diagrammatic reasoning systems that are inherently different from symbolic logics due to natural geometric constraints. We provide a particular concrete transformation system which preserves the important criteria of planarity and connectivity, which may form part of a framework encompassing multiple concrete systems each adhering to different sets of wellformedness conditions

Euler diagram transformations

Euler diagrams are a visual language which are used for purposes such as the presentation of set-based data or as the basis of visual logical languages which can be utilised for software specification and reasoning. Such Euler diagram reasoning systems tend to be defined at an abstract level, and the concrete level is simply a visualisation of an abstract model, thereby capturing some subset of the usual boolean logic. The visualisation process tends to be divorced from the data transformation process thereby affecting the user’s mental map and reducing the effectiveness of the diagrammatic notation. Furthermore, geometric and topological constraints, called wellformedness conditions, are often placed on the concrete diagrams to try to reduce human comprehension errors, and the effects of these conditions are not modelled in these systems. We view Euler diagrams as a type of graph, where the faces that are present are the key features that convey information and we provide transformations at the dual graph level that correspond to transformations of Euler diagrams, both in terms of editing moves and logical reasoning moves. This original approach gives a corre

A Task-Based Evaluation of Combined Set and Network Visualization

This paper addresses the problem of how best to visualize network data grouped into overlapping sets. We address it by evaluating various existing techniques alongside a new technique. Such data arise in many areas, including social network analysis, gene expression data, and crime analysis. We begin by investigating the strengths and weakness of four existing techniques, namely Bubble Sets, EulerView, KelpFusion, and LineSets, using principles from psychology and known layout guides. Using insights gained, we propose a new technique, SetNet, that may overcome limitations of earlier methods. We conducted a comparative crowdsourced user study to evaluate all five techniques based on tasks that require information from both the network and the sets. We established that EulerView and SetNet, both of which draw the sets first, yield significantly faster user responses than Bubble Sets, KelpFusion and LineSets, all of which draw the network first

A cognitive exploration of the “non-visual” nature of geometric proofs

Why are Geometric Proofs (Usually) “Non-Visual”? We asked this question as a way to explore the similarities and differences between diagrams and text (visual thinking versus language thinking). Traditional text-based proofs are considered (by many to be) more rigorous than diagrams alone. In this paper we focus on human perceptual-cognitive characteristics that may encourage textual modes for proofs because of the ergonomic affordances of text relative to diagrams. We suggest that visual-spatial perception of physical objects, where an object is perceived with greater acuity through foveal vision rather than peripheral vision, is similar to attention navigating a conceptual visual-spatial structure. We suggest that attention has foveal-like and peripheral-like characteristics and that textual modes appeal to what we refer to here as foveal-focal attention, an extension of prior work in focused attention

Designing and Publishing Indoor Maps for Patients and Visitors in an Academic Teaching Hospital

Introduction. This project aims to improve the service user experience by designing and publishing an accessible indoor map in an academic teaching hospital. On a daily basis approximately 600 service users will be disoriented in the hospital resulting in 18 hours/day staff time spent helping patients find their way. 84% (n=109) of staff categorised indoor maps as a service improvement. Patients who get lost can feel anxiety, shame and even panic. Maps can improve patient autonomy¹. Internationally hospitals develop a wayfinding strategy to co-ordinate information received by service users. Initiation. Volunteer-run project survey (n=175) showed 84% of disoriented patients would have liked a map. Up to 18 hours/day staff time is invested in re-orientating approximately 600 patients daily. Planning. Analysis of service user locations included signs, directions, and kiosk locations. Tool choice was Adobe Illustrator CS6 (Adobe, 2014) to create paper maps. Maps available in leaflet form, on the reverse of a letter or as a kiosk ticket. Implementation. The map was endorsed by senior management and published on the hospital website. Development time was 80 hours but project was cost neutral. Adopting maps will cost €1700 annually (1c/letter). Evaluation. MAPQUAL quality framework² gave a medium-high map quality score, issues identified with signage accuracy (69%) affecting map clarity, usefulness and availability through patient letters. Conclusion. The HSE Change Model³ supports developing innovation projects but mainstreaming may require further research where change disrupts processes. Irish hospitals should develop wayfinding strategies to deliver information consistency across hospital groups for service user

Visualizing Set Relations and Cardinalities Using Venn and Euler Diagrams

In medicine, genetics, criminology and various other areas, Venn and Euler diagrams are used to visualize data set relations and their cardinalities. The data sets are represented by closed curves and the data set relationships are depicted by the overlaps between these curves. Both the sets and their intersections are easily visible as the closed curves are preattentively processed and form common regions that have a strong perceptual grouping effect. Besides set relations such as intersection, containment and disjointness, the cardinality of the sets and their intersections can also be depicted in the same diagram (referred to as area-proportional) through the size of the curves and their overlaps. Size is a preattentive feature and so similarities, differences and trends are easily identified. Thus, such diagrams facilitate data analysis and reasoning about the sets. However, drawing these diagrams manually is difficult, often impossible, and current automatic drawing methods do not always produce appropriate diagrams. This dissertation presents novel automatic drawing methods for different types of Euler diagrams and a user study of how such diagrams can help probabilistic judgement. The main drawing algorithms are: eulerForce, which uses a force-directed approach to lay out Euler diagrams; eulerAPE, which draws area-proportional Venn diagrams with ellipses. The user study evaluated the effectiveness of area- proportional Euler diagrams, glyph representations, Euler diagrams with glyphs and text+visualization formats for Bayesian reasoning, and a method eulerGlyphs was devised to automatically and accurately draw the assessed visualizations for any Bayesian problem. Additionally, analytic algorithms that instantaneously compute the overlapping areas of three general intersecting ellipses are provided, together with an evaluation of the effectiveness of ellipses in drawing accurate area-proportional Venn diagrams for 3-set data and the characteristics of the data that can be depicted accurately with ellipses