Towards Coordination-Intensive Visualization Software

Most coordination realizations in current visualization systems are ''last-minute'' ad-hoc and rely on the richness of the chosen implementation language. Moreover, very few visualization models implicitly consider coordination. If coordination is contemplated from the design point of view, it is usually only regarded as part of the communication protocol and is generally dealt with within that restricted domain. Coordinated multiple views are beneficial and a flexible model for coordination will ensure easy embedding of coordination in such exploratory environments. This paper compares different approaches to coordination in exploratory visualization (EV). We recognize the need for a coordination model and for that we formalize aspects of coordination in EV. Furthermore, our work draws on the findings of the interdisciplinary study of coordination by various researchers

Sketchy rendering for information visualization

We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These primitives allow higher-level graphical features such as bar charts, line charts, treemaps and node-link diagrams to be drawn in a sketchy style with a specified degree of sketchiness. The framework is designed to be easily integrated into existing visualization implementations with minimal programming modification or design effort. We show examples of use for statistical graphics, conveying spatial imprecision and for enhancing aesthetic and narrative qualities of visual- ization. We evaluate user perception of sketchiness of areal features through a series of stimulus-response tests in order to assess users’ ability to place sketchiness on a ratio scale, and to estimate area. Results suggest relative area judgment is compromised by sketchy rendering and that its influence is dependent on the shape being rendered. They show that degree of sketchiness may be judged on an ordinal scale but that its judgement varies strongly between individuals. We evaluate higher-level impacts of sketchiness through user testing of scenarios that encourage user engagement with data visualization and willingness to critique visualization de- sign. Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive. The results of our work have implications for effective information visualization design that go beyond the traditional role of sketching as a tool for prototyping or its use for an indication of general uncertainty

SEEING THE UNSEEN: DELIVERING INTEGRATED UNDERGROUND UTILITY DATA IN THE UK

In earlier work we proposed a framework to integrate heterogeneous geospatial utility data in the UK. This paper provides an update on the techniques used to resolve semantic and schematic heterogeneities in the UK utility domain. Approaches for data delivery are discussed, including descriptions of three pilot projects and domain specific visualization issues are considered. A number of practical considerations are discussed that will impact on how any implementation architecture is derived from the integration framework. Considerations of stability, security, currency, operational impact and response time can reveal a number of conflicting constraints. The impacts of these constraints are discussed in respect of either a virtual or materialised delivery system. 1

Understanding alternatives in data analysis activities

Data workers are non-professional data scientists who engage in data analysis activities as part of their daily work. In this position paper, we share past and on-going work to understand data workers’ sense-making practices. We use multidisciplinary approaches to explore their human-tool partnerships. We introduce our current research on the role of alternatives in data analysis activities. Finally, we conclude with open questions and research directions

GraphUnit: Evaluating Interactive Graph Visualizations Using Crowdsourcing

We present GraphUnit, a framework and online service that automates the process of designing, running and analyzing results of controlled user studies of graph visualizations by leveraging crowdsourcing and a set of evaluation modules based on a graph task taxonomy. User studies play an important role in visualization research but conducting them requires expertise and is time consuming. GraphUnit simplifies the evaluation process by allowing visualization designers to easily configure user studies for their web-based graph visualizations, deploy them online, use Mechanical Turk to attract participants, collect user responses and store them in a database, and analyze incoming results automatically using appropriate statistical tools and graphs. We demonstrate the effectiveness of GraphUnit by replicating two published evaluation studies on network visualization, and showing that these studies could be configured in less than an hour. Finally, we discuss how GraphUnit can facilitate quick evaluations of alternative graph designs and thus encourage the frequent use of user studies to evaluate design decisions in iterative development processes

A Mixed Approach for the Evaluation of a Guided Exploratory Visualization System

HAL Id : hal-01153887, version 1 HAL Id : hal-01153887, version 1International audienceWe summarise and reflect upon our experience in evaluating a guided exploratory visualization system. Our system guides users in their exploration of multidimensional datasets to pertinent views of their data, where the notion of pertinence is defined by automatic indicators, such as the amount of visual patterns in the view, and subjective user feedback obtained during their interaction with the tool. To evaluate this type of system, we argue for deploying a collection of validation methods that are: user-centered, observing the utility and effectiveness of the system for the end-user; and algorithm-centered, analysing the computational behaviour of the system. We report on observations and lessons learnt from working with expert users both for the design and the evaluation of our system

EvoGraphDice: Interactive Evolution for Visual Analytics

International audienceVisualization of large and complex datasets is a research challenge, especially in frameworks like industrial design, decision making and visual analytics. Interactive Evolution, used not only as an optimisation tool, but also as an exploration tool may provide some versatile solutions to this challenge. This paper presents an attempt in this direction with the EvoGraphDice prototype, developed on top of GraphDice, a general purpose visualization freeware for multidimensional visualization based on scatterplot matrices. EvoGraphDice interactively evolves compound additional dimensions, that provide new viewpoints on a multidimensional dataset. Compound dimensions are linear combination of the initial data dimensions, they are initialised with a Principal Component Analysis (PCA), and modified progressively by the interactive evolution process. Various interactions are available to the user, either in a transparent way, via a capture of mouse-clicks, or in a fully controlled manner, where the user has the opportunity to modify or include his own compound dimension in the evolved population, control the earch space, or do some interactive queries. EvoGraphDice is tested on a synthetic dataset of dimension 6, where a known dependency is rediscovered via interactive manipulation. A second example is presented, based on a real dataset of dimension 13, provided by an industrial partner. Our experiments prove the potential of this interactive approach, and allow us to sketch future directions of development for the EvoGraphDice prototype

Target Deletion of the Cytoskeleton-Associated Protein Palladin Does Not Impair Neurite Outgrowth in Mice

Palladin is an actin cytoskeleton–associated protein which is crucial for cell morphogenesis and motility. Previous studies have shown that palladin is localized to the axonal growth cone in neurons and may play an important role in axonal extension. Previously, we have generated palladin knockout mice which display cranial neural tube closure defect and embryonic lethality before embryonic day 15.5 (E15.5). To further study the role of palladin in the developing nervous system, we examined the innervation of palladin-deficient mouse embryos since the 200 kd, 140 kd, 90–92 kd and 50 kd palladin isoforms were undetectable in the mutant mouse embryo brain. Contrary to the results of previous studies, we found no inhibition of the axonal extension in palladin-deficient mouse embryos. The cortical neurons derived from palladin-deficient mice also showed no significant difference in neurite outgrowth as compared with those from wild-type mice. Moreover, no difference was found in neurite outgrowth of neural stem cell derived-neurons between palladin-deficient mice and wild-type mice. In conclusion, these results suggest that palladin is dispensable for normal neurite outgrowth in mice

Evaluating Sketchy Lines for the Visualization of Qualitative Uncertainty

We report on results of a series of user studies on the perception of visual variables that are commonly used in the literature to depict uncertainty. To the best of our knowledge, we provide the first formal evaluation of the use of these variables to facilitate an easier reading of uncertainty in visualizations that rely on line graphical primitives. In addition to blur, dashing and grayscale, we investigate the use of 'sketchiness' as a visual variable because it conveys visual impreciseness that may be associated with data quality. Inspired by work in non-photorealistic rendering and by the features of hand-drawn lines, we generate line trajectories that resemble hand-drawn strokes of various levels of proficiency--ranging from child to adult strokes--where the amount of perturbations in the line corresponds to the level of uncertainty in the data. Our results show that sketchiness for the visualization of uncertainty in lines is as intuitive as blur; although people subjectively prefer dashing style over blur, grayscale and sketchiness. We discuss advantages and limitations of each technique and conclude with design considerations on how to deploy these visual variables to effectively depict various levels of uncertainty for line marks.Nous rapportons les résultats d'études utilisateurs sur la perception de variables visuelles qui sont couramment utilisées dans la littérature pour représenter l'incertitude. A notre connaissance, nous rapportons la première évaluation formelle de l'utilisation de ces variables pour faciliter la lecture de l'incertitude dans des visualisations qui reposent sur des lignes graphiques primitives. En plus du flouté, des pointillés et des niveaux de gris, nous avons étudié l'utilisation du dessin á main levée comme variable visuelle parce qu'il transmet l'imprécision qui peut être associée á la qualité des données. Inspirés par les travaux sur NPR (Non-Photorealistic Rendering) et par l'aspect des lignes tracées á la main, nous avons généré des trajectoires linéaires ressemblant á des traits dessinés á la main, et correspondant á différents niveaux de compétence--allant de l'enfant á l'adulte--pour lesquels la quantité de perturbations dans la ligne correspondait au niveau d'incertitude des données. Nos résultats montrent que l'utilisation du dessin á main levée pour la visualisation de l'incertitude dans les lignes est aussi intuitive que le flouté, bien qu'intuitivement les personnes préfèrent subjectivement les pointillés au flou, aux niveaux de gris ainsi qu'au dessin á main levée. Nous discutons les avantages et les limites de chaque technique et nous concluons sur des considérations de conception, concernant comment déployer ces variables visuelles pour représenter efficacement plusieurs niveaux d'incertitude pour des repères linéaires

Supporting Historical Research Through User-Centered Visual Analytics

International audienceIn this paper we describe the development and evaluation of a visual analytics tool to support historical research. Historians continuously gather data related to their scholarly research from archival visits and background search. Organising and making sense of all this data can be challenging as many historians continue to rely on analog or basic digital tools. We built an integrated note-taking environment for historians which unifies a set of func-tionalities we identified as important for historical research including editing, tagging, searching, sharing and visualization. Our approach was to involve users from the initial stage of brainstorming and requirement analysis through to design, implementation and evaluation. We report on the process and results of our work, and conclude by reflecting on our own experience in conducting user-centered visual analytics design for digital humanities