Informatics

3208 KiB

Open AccessArticle

Interactive Graph Layout of a Million Nodes

by Peng Mi, Maoyuan Sun, Moeti Masiane, Yong Cao and Chris North

Informatics 2016, 3(4), 23; https://doi.org/10.3390/informatics3040023 - 20 Dec 2016

Cited by 13 | Viewed by 11142

Sensemaking of large graphs, specifically those with millions of nodes, is a crucial task in many fields. Automatic graph layout algorithms, augmented with real-time human-in-the-loop interaction, can potentially support sensemaking of large graphs. However, designing interactive algorithms to achieve this is challenging. In [...] Read more.

Sensemaking of large graphs, specifically those with millions of nodes, is a crucial task in many fields. Automatic graph layout algorithms, augmented with real-time human-in-the-loop interaction, can potentially support sensemaking of large graphs. However, designing interactive algorithms to achieve this is challenging. In this paper, we tackle the scalability problem of interactive layout of large graphs, and contribute a new GPU-based force-directed layout algorithm that exploits graph topology. This algorithm can interactively layout graphs with millions of nodes, and support real-time interaction to explore alternative graph layouts. Users can directly manipulate the layout of vertices in a force-directed fashion. The complexity of traditional repulsive force computation is reduced by approximating calculations based on the hierarchical structure of multi-level clustered graphs. We evaluate the algorithm performance, and demonstrate human-in-the-loop layout in two sensemaking case studies. Moreover, we summarize lessons learned for designing interactive large graph layout algorithms on the GPU. Full article

(This article belongs to the Special Issue Information Visualization for Massive Data)

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262 KiB

Open AccessConcept Paper

How Thumbelina Knows

by Giorgio De Michelis

Informatics 2016, 3(4), 22; https://doi.org/10.3390/informatics3040022 - 16 Nov 2016

Cited by 3 | Viewed by 8464

Abstract

In this paper, I take the book by Michel Serres, “Thumbelina”, as an occasion for reflection on the conceptual basis of knowledge management, as was built by Nonaka and co-workers. The direct access to knowledge that Thumbelina practices together with her peers is, [...] Read more.

In this paper, I take the book by Michel Serres, “Thumbelina”, as an occasion for reflection on the conceptual basis of knowledge management, as was built by Nonaka and co-workers. The direct access to knowledge that Thumbelina practices together with her peers is, in fact, for me, and is a good observation point to bring Nonaka’s reflection further towards the discovery of a new understanding of knowledge and knowing processes. If the digital revolution is the third step, after writing and printing, regarding the soft changes in the relations between human beings and knowledge, then it highlights the urgent problem of deepening our understanding of what knowledge and intelligence are, changing our practices at the educational level, and designing new digital tools to support our knowledge management processes. Full article

(This article belongs to the Special Issue Social Computing for Knowledge Management)

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1026 KiB

Open AccessArticle

Disabling and Enabling Technologies for Learning in Higher Education for All: Issues and Challenges for Whom?

by Sangeeta Bagga-Gupta, Giulia Messina Dahlberg and Ylva Winther

Informatics 2016, 3(4), 21; https://doi.org/10.3390/informatics3040021 - 28 Oct 2016

Cited by 11 | Viewed by 9117

Abstract

Integration, inclusion, and equity constitute fundamental dimensions of democracy in post-World War II societies and their institutions. The study presented here reports upon the ways in which individuals and institutions both use and account for the roles that technologies, including ICT, play in [...] Read more.

Integration, inclusion, and equity constitute fundamental dimensions of democracy in post-World War II societies and their institutions. The study presented here reports upon the ways in which individuals and institutions both use and account for the roles that technologies, including ICT, play in disabling and enabling access for learning in higher education for all. Technological innovations during the 20th and 21st centuries, including ICT, have been heralded as holding significant promise for revolutionizing issues of access in societal institutions like schools, healthcare services, etc. (at least in the global North). Taking a socially oriented perspective, the study presented in this paper focuses on an ethnographically framed analysis of two datasets that critically explores the role that technologies, including ICT, play in higher education for individuals who are “differently abled” and who constitute a variation on a continuum of capabilities. Functionality as a dimension of everyday life in higher education in the 21st century is explored through the analysis of (i) case studies of two “differently abled” students in Sweden and (ii) current support services at universities in Sweden. The findings make visible the work that institutions and their members do through analyses of the organization of time and space and the use of technologies in institutional settings against the backdrop of individuals’ accountings and life trajectories. This study also highlights the relevance of multi-scale data analyses for revisiting the ways in which identity positions become framed or understood within higher education. Full article

(This article belongs to the Special Issue Information and Communication Technology in Higher Education)

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12274 KiB

Open AccessArticle

Supporting Sensemaking of Complex Objects with Visualizations: Visibility and Complementarity of Interactions

by Kamran Sedig, Paul Parsons, Hai-Ning Liang and Jim Morey

Informatics 2016, 3(4), 20; https://doi.org/10.3390/informatics3040020 - 28 Oct 2016

Cited by 15 | Viewed by 12102

Abstract

Making sense of complex objects is difficult, and typically requires the use of external representations to support cognitive demands while reasoning about the objects. Visualizations are one type of external representation that can be used to support sensemaking activities. In this paper, we [...] Read more.

Making sense of complex objects is difficult, and typically requires the use of external representations to support cognitive demands while reasoning about the objects. Visualizations are one type of external representation that can be used to support sensemaking activities. In this paper, we investigate the role of two design strategies in making the interactive features of visualizations more supportive of users’ exploratory needs when trying to make sense of complex objects. These two strategies are visibility and complementarity of interactions. We employ a theoretical framework concerned with human–information interaction and complex cognitive activities to inform, contextualize, and interpret the effects of the design strategies. The two strategies are incorporated in the design of Polyvise, a visualization tool that supports making sense of complex four-dimensional geometric objects. A mixed-methods study was conducted to evaluate the design strategies and the overall usability of Polyvise. We report the findings of the study, discuss some implications for the design of visualization tools that support sensemaking of complex objects, and propose five design guidelines. We anticipate that our results are transferrable to other contexts, and that these two design strategies can be used broadly in visualization tools intended to support activities with complex objects and information spaces. Full article

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1741 KiB

Open AccessArticle

Ubiquitous Learning Architecture to Enable Learning Path Design across the Cumulative Learning Continuum

by Konstantinos Karoudis and George D. Magoulas

Informatics 2016, 3(4), 19; https://doi.org/10.3390/informatics3040019 - 11 Oct 2016

Cited by 8 | Viewed by 9951

Abstract

The past twelve years have seen ubiquitous learning (u-learning) emerging as a new learning paradigm based on ubiquitous technology. By integrating a high level of mobility into the learning environment, u-learning enables learning not only through formal but also through informal and social [...] Read more.

The past twelve years have seen ubiquitous learning (u-learning) emerging as a new learning paradigm based on ubiquitous technology. By integrating a high level of mobility into the learning environment, u-learning enables learning not only through formal but also through informal and social learning modalities. This makes it suitable for lifelong learners that want to explore, identify and seize such learning opportunities, and to fully build upon these experiences. This paper presents a theoretical framework for designing personalized learning paths for lifelong learners, which supports contemporary pedagogical approaches that can promote the idea of a cumulative learning continuum from pedagogy through andragogy to heutagogy where lifelong learners progress in maturity and autonomy. The framework design builds on existing conceptual and process models for pedagogy-driven design of learning ecosystems. Based on this framework, we propose a system architecture that aims to provide personalized learning pathways using selected pedagogical strategies, and to integrate formal, informal and social training offerings using two well-known learning and development reference models; the 70:20:10 framework and the 3–33 model. Full article

(This article belongs to the Special Issue Ubiquitous Computing: From Interlinking Smart Tabs, Pads and Boards towards Interlinking Smart Skins, Dust and Clay)

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2138 KiB

Open AccessArticle

AVIST: A GPU-Centric Design for Visual Exploration of Large Multidimensional Datasets

by Peng Mi, Maoyuan Sun, Moeti Masiane, Yong Cao and Chris North

Informatics 2016, 3(4), 18; https://doi.org/10.3390/informatics3040018 - 7 Oct 2016

Cited by 2 | Viewed by 8423

Abstract

This paper presents the Animated VISualization Tool (AVIST), an exploration-oriented data visualization tool that enables rapidly exploring and filtering large time series multidimensional datasets. AVIST highlights interactive data exploration by revealing fine data details. This is achieved through the use of animation and [...] Read more.

This paper presents the Animated VISualization Tool (AVIST), an exploration-oriented data visualization tool that enables rapidly exploring and filtering large time series multidimensional datasets. AVIST highlights interactive data exploration by revealing fine data details. This is achieved through the use of animation and cross-filtering interactions. To support interactive exploration of big data, AVIST features a GPU (Graphics Processing Unit)-centric design. Two key aspects are emphasized on the GPU-centric design: (1) both data management and computation are implemented on the GPU to leverage its parallel computing capability and fast memory bandwidth; (2) a GPU-based directed acyclic graph is proposed to characterize data transformations triggered by users’ demands. Moreover, we implement AVIST based on the Model-View-Controller (MVC) architecture. In the implementation, we consider two aspects: (1) user interaction is highlighted to slice big data into small data; and (2) data transformation is based on parallel computing. Two case studies demonstrate how AVIST can help analysts identify abnormal behaviors and infer new hypotheses by exploring big datasets. Finally, we summarize lessons learned about GPU-based solutions in interactive information visualization with big data. Full article

(This article belongs to the Special Issue Information Visualization for Massive Data)

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758 KiB

Open AccessArticle

Direct Visual Editing of Node Attributes in Graphs

by Christian Eichner, Stefan Gladisch, Heidrun Schumann and Christian Tominski

Informatics 2016, 3(4), 17; https://doi.org/10.3390/informatics3040017 - 1 Oct 2016

Cited by 8 | Viewed by 8354

Abstract

There are many expressive visualization techniques for analyzing graphs. Yet, there is only little research on how existing visual representations can be employed to support data editing. An increasingly relevant task when working with graphs is the editing of node attributes. We propose [...] Read more.

There are many expressive visualization techniques for analyzing graphs. Yet, there is only little research on how existing visual representations can be employed to support data editing. An increasingly relevant task when working with graphs is the editing of node attributes. We propose an integrated visualize-and-edit approach to editing attribute values via direct interaction with the visual representation. The visualize part is based on node-link diagrams paired with attribute-dependent layouts. The edit part is as easy as moving nodes via drag-and-drop gestures. We present dedicated interaction techniques for editing quantitative as well as qualitative attribute data values. The benefit of our novel integrated approach is that one can directly edit the data while the visualization constantly provides feedback on the implications of the data modifications. Preliminary user feedback indicates that our integrated approach can be a useful complement to standard non-visual editing via external tools. Full article

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Informatics, Volume 3, Issue 4 (December 2016) – 7 articles

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