Lukas Zenk

A visual analytics approach to dynamic social networks

The visualization and analysis of dynamic networks have become increasingly important in several fields, for instance sociology or economics. The dynamic and multi-relational nature of this data poses the challenge of understanding both its topological structure and how it changes over time. In this paper we propose a visual analytics approach for analyzing dynamic networks that integrates: a dynamic layout with user-controlled trade-off between stability and consistency; three temporal views based on different combinations of node-link diagrams (layer superimposition, layer juxtaposition, and two-and-a-half-dimensional view); the visualization of social network analysis metrics; and specific interaction techniques for tracking node trajectories and node connectivity over time. This integration of visual, interactive, and automatic methods supports the multi-faceted analysis of dynamically changing networks.

Visual Analysis of Dynamic Networks Using Change Centrality

The visualization and analysis of dynamic social networks are challenging problems, demanding the simultaneous consideration of relational and temporal aspects. In order to follow the evolution of a network over time, we need to detect not only which nodes and which links change and when these changes occur, but also the impact they have on their neighbourhood and on the overall relational structure. Aiming to enhance the perception of structural changes at both the micro and the macro level, we introduce the change centrality metric. This novel metric, as well as a set of further metrics we derive from it, enable the pair wise comparison of subsequent states of an evolving network in a discrete-time domain. Demonstrating their exploitation to enrich visualizations, we show how these change metrics support the visual analysis of network dynamics.

How Do You Connect Moving Dots? Insights from User Studies on Dynamic Network Visualizations

In recent years, the analysis of dynamic network data has become an increasingly prominent research issue. While several visual analytics techniques with the focus on the examination of temporal evolving networks have been proposed in recent years, their effectiveness and utility for end users need to be further analyzed. When dealing with techniques for dynamic network analysis, which integrate visual, computational, and interactive components, users become easily overwhelmed by the amount of information displayed—even in case of small sized networks. Therefore we evaluated visual analytics techniques for dynamic networks during their development, performing intermediate evaluations by means of mock-up and eye-tracking studies and a final evaluation of the running interactive prototype, traceing three pathways of development in detail: The first one focused on the maintenance of the user’s mental map throughout changes of network structure over time, changes caused by user interactions, and changes of analytical perspectives. The second one addresses the avoidance of visual clutter, or at least its moderation. The third pathway of development follows the implications of unexpected user behaviour and multiple problem solving processes. Aside from presenting solutions based on the outcomes of our evaluation, we discuss open and upcoming problems and set out new research questions.

Situated Organizational Mapping

So allgegenwartig Organisationen in der modernen Gesellschaft auch sind und so unverzichtbar sie zu Regelung und Erhalt aller Lebensbereiche auch sein mogen, so allgegenwartig sind auch Phanomene der Intransparenz oder Unverstandlichkeit dieser komplexen sozialen Systeme fur externe Beobachter und interne Mitglieder1. Dies gilt prinzipiell fur grosere Organisationen in jeglichem Funktionsbereich, insbesondere aber fur knowledgeintensive firms, d.h. Unternehmen in denen komplexe (immaterielle und unsichtbare) Wissensarbeit eine zentrale Rolle spielt.

Collaborative team networks and implications for strategic HRM

Using longitudinal data from a graduate course (with 97 students grouped into 18 teams) we analyze the emergence of collaborative working patterns and the influence of personal traits on team performance and individual team member satisfaction. We find a positive effect of global centrality measures on individual satisfaction, while local centrality measures did not have a significant impact. Moreover, our results indicate that the aggregation of power within working teams is detrimental for team performance. When some individuals are in a position that allows them to exert power over others, the performance of teams suffers. On the contrary, betweenness centralization, which could enable some people to broker information across unconnected actors, could actually be beneficial for teams and increases overall performance. We conclude that combining information on team demographics and social networks might allow inferences into why certain teams perform better than others and into which areas human resource measures should be directed to improve team performance.

A Concept for the Exploratory Visualization of Patent Network Dynamics

Patents, archived as large collections of semi-structured text documents, contain valuable information about historical trends and current states of R&D fields, as well as performances of single inventors and companies. Specific methods are needed to unlock this information and enable its insightful analysis by investors, executives, funding agencies, and policy makers. In this position paper, we propose an approach based on modelling patent repositories as multivariate temporal networks, and examining them by the means of specific visual analytics methods. We illustrate the potential of our approach by discussing two use-cases: the determination of emerging research fields in general and within companies, as well as the identification of inventors characterized by different temporal paths of productivity.

Management of Situated E-Learning in Organizations

Complex products and services require both the sophisticated knowledge of individuals on the one hand and collective collaboration between various disciplines and teams on the other. Work-related individual and organizational learning processes in organizations appear to provide the foundations for such individual and organizational knowledge and capabilities. These interconnected learning processes would also seem to be situated in both a social and a physical environment. This paper proposes a methodology for managing situated individual and organizational learning. Empirical results from a questionnaire and two test bed organizations are presented and conclusions drawn from the assessment results on recommended measures for the use of e-learning.

Conferences, Coffee and Complexity: Supporting Cognition and Communication at Conventions

This article takes information visualization to the field of academic conferences and conventions, to explore how cognition and communication of participants could be supported in such ephemeral, knowledge-intensive environments. With focus on a non-invasive method of data collection, we consider the levels of topical, social, temporal and spatial orientation as primary working areas for any support system. Across these areas, overviews and personalized detail-views have to be intertwined, to allow for the localization and navigation of individual participants. To demonstrate a lean approach to these challenges, we introduce a visual conference exploration system, that allows participants to visually explore conferences before, during and after their attendance and support their personal knowledge management by making use of recommendations, which help to establish new contacts, or find the most interesting panels and talks.

Netzwerkforschung in der Kognitionswissenschaft Kognitionswissenschaft als Netzwerkforschung

Die Kognitionswissenschaft ist ein junges transdisziplinares Forschungsfeld. Ihr Gegenstand ist die Fahigkeit von Lebewesen sich intelligent zu verhalten. Sie versucht die individuelle und artenspezifische Entwicklung intelligenter Verhaltensweisen (wie Wahrnehmung, Denken, Lernen, Motorik, Emotion, Aufmerksamkeit, Sprache) durch Modelle und Simulationen zu erklaren. In Weiterfuhrung dessen untersucht sie auch die Moglichkeit der Kognition bzw. der Intelligenz von kunstlichen Systemen (Kunstliche Intelligenz). Der kognitionswissenschaftliche Diskurs findet dabei in wechselnden Gewichtungen und Vernetzungen uber den disziplinaren Feldern der Psychologie, Informatik, Neurowissenschaft, Linguistik, Anthropologie und Philosophie statt (Thagard 1996; Friedenberg und Silverman 2006).

Strategic E-Learning in the Workplace

Empirical research suggests that there is an impact of organizational characteristics on individual work-related learning processes. In this paper, we propose a model of relevant organizational factors. An assessment methodology based on a literature survey and activity theory is summarized. First results of an empirical validation are presented with an emphasis on prerequisites for e-learning.