Stephan Diehl
University of Trier, Computer Science, Department Member
Abstract 1. The experiment investigated whether controlling presentation speed as well as labels, which display the names of the currently presented nodes in interactive dynamic graphs, affects comprehension performance. Dynamic graphs... more
Abstract 1. The experiment investigated whether controlling presentation speed as well as labels, which display the names of the currently presented nodes in interactive dynamic graphs, affects comprehension performance. Dynamic graphs are animated graphical ...
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ABSTRACT
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Software repositories such as source control systems,defect tracking systems,or archived communications between project personnel are used to help manage the progress of software projects.Software practitioners and researchers are... more
Software repositories such as source control systems,defect tracking systems,or archived communications between project personnel are used to help manage the progress of software projects.Software practitioners and researchers are beginning to recognize the potential bene .t of mining this information to support the maintenance of software systems,improve software design/reuse,and empirically validate novel ideas and techniques.Research is now proceeding to uncover the
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In this paper we present a generic algorithm for drawing sequences of graphs. This algorithm works for different layout algorithms and related metrics and adjustment strategies. It differs from previous work on dynamic graph drawing in... more
In this paper we present a generic algorithm for drawing sequences of graphs. This algorithm works for different layout algorithms and related metrics and adjustment strategies. It differs from previous work on dynamic graph drawing in that it considers all graphs in the sequence (offline) instead of just the previous ones (online) when computing the layout for each graph of
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In this paper we present a generic algorithm for drawing se- quences of graphs. This algorithm works for different layout algorithms and related metrics and adjustment strategies. It differs from previous work on dynamic graph drawing in... more
In this paper we present a generic algorithm for drawing se- quences of graphs. This algorithm works for different layout algorithms and related metrics and adjustment strategies. It differs from previous work on dynamic graph drawing in that it considers all graphs in the sequence (offline) instead of just the previous ones (online) when com- puting the layout for each
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In this paper we present a generic algorithm for drawing sequences of graphs. This algorithm works for different layout algorithms and related metrics and adjustment strategies. It differs from previous work on dynamic graph drawing in... more
In this paper we present a generic algorithm for drawing sequences of graphs. This algorithm works for different layout algorithms and related metrics and adjustment strategies. It differs from previous work on dynamic graph drawing in that it considers all graphs in the sequence (offline) instead of just the previous ones (online) when computing the layout for each graph of the sequence. We introduce several general adjustment strategies and give examples of these strategies in the context of force-directed graph layout. Finally some results from our first prototype implementation are discussed.
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ABSTRACT During early phases of a software development process co-located group work is an important technique that involves all stakeholders to derive requirements and a design of a future software system. However, such group work is... more
ABSTRACT During early phases of a software development process co-located group work is an important technique that involves all stakeholders to derive requirements and a design of a future software system. However, such group work is usually applied without any computer-assistance and often faces the problem that information is not well preserved for subsequent steps. In order to examine whether group work benefits from computer-assistance, we developed CREWSpace. It leverages mobile devices to allow simultaneous interaction with a shared software model. In particular, it implements a digital variant of the CRC method. In this paper, we discuss advantages and disadvantages of the traditional CRC method, briefly introduce CREWSpace along with important implementation details, and focus on a qualitative usability study. Its results suggest that our prototype keeps the advantages of traditional CRC method and compensates many of its weaknesses.
ABSTRACT Object-orientation is one of the essential parts of every software engineering course. However, according to literature, it often lacks the following: First, modeling on a conceptual level independent from a particular... more
ABSTRACT Object-orientation is one of the essential parts of every software engineering course. However, according to literature, it often lacks the following: First, modeling on a conceptual level independent from a particular programming language is often neglected. Moreover, the actual process of designing or implementing a piece of software seems to be less important than providing an optimal solution. Finally, students often follow the slides of the teacher passively without thinking about or even questioning the material. But, in order to actively apply a proper form of object-orientation, it is essential that one understands the concepts of this programming paradigm and is able to deal with problems and communicate ideas rather than handling a specific programming language. In this paper we introduce CREWSpace-a tool for co-located collaboration that implements a digital version of the CRC method. To this end, students actively participate in so called CRC sessions, which fosters communication and problem solving skills. In particular, they design a software system on a conceptual level and use our tool to analyze and adjust the proposed design through role play. Moreover, CREWSpace records these analyses for a later replay such that the students are able to reflect on their decisions.
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Many recently developed information visualization techniques are radial variants of originally Cartesian visualizations. Almost none of these radial variants have been evaluated with respect to their benefits over their original... more
Many recently developed information visualization techniques are radial variants of originally Cartesian visualizations. Almost none of these radial variants have been evaluated with respect to their benefits over their original visualizations. In this work we compare a radial and a Cartesian variant of a visualization tool for sequences of transactions in information hierarchies. The Timeline Trees (TLT) approach uses a Cartesian coordinate system to represent both the hierarchy and the sequence of transactions whereas the TimeRadarTrees (TRT) technique is the radial counterpart which makes use of a radial tree, as well as circle slices and sectors to show the sequence of transactions. For the evaluation we use both quantitative as well as qualitative evaluation methods including eye tracking.
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Most research on the readability of graph visualization focuses on node-link diagrams of static graphs. But in many applications graphs are not static, but change over time, or graphs are too dense to be drawn as node-link diagrams. In... more
Most research on the readability of graph visualization focuses on node-link diagrams of static graphs. But in many applications graphs are not static, but change over time, or graphs are too dense to be drawn as node-link diagrams. In this paper we look at dynamic graph visualizations: We translate the general goal of graph visualization-to convey the underlying information of a graph-into aesthetic dimensions that are applicable in practice. These aesthetic dimensions help to design, compare, and evaluate dynamic graph visualizations.
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We apply data mining to version histories in order to guide programmers along related changes: "Programmers who changed these functions also changed...." Given a set of existing changes, the mined association rules 1) suggest and predict... more
We apply data mining to version histories in order to guide programmers along related changes: "Programmers who changed these functions also changed...." Given a set of existing changes, the mined association rules 1) suggest and predict likely further changes, 2) show up item coupling that is undetectable by program analysis, and 3) can prevent errors due to incomplete changes. After an initial change, our ROSE prototype can correctly predict further locations to be changed; the best predictive power is obtained for changes to existing software. In our evaluation based on the history of eight popular open source projects, ROSE's topmost three suggestions contained a correct location with a likelihood of more than 70 percent.
Research Interests: Information Systems, History, Computer Science, Software Maintenance, Data Mining, and 15 moreDocumentation, Environmental Management, Program Analysis, Configuration Management, DISTRIBUTION, Navigation, Computer Software, Clustering, HTML, Classification, Prototypes, Association Rules, Capture recapture, Distribution, and Association Rule
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ABSTRACT During early phases of a software development process co-located group work is an important technique that involves all stakeholders to derive requirements and a design of a future software system. However, such group work is... more
ABSTRACT During early phases of a software development process co-located group work is an important technique that involves all stakeholders to derive requirements and a design of a future software system. However, such group work is usually applied without any computer-assistance and often faces the problem that information is not well preserved for subsequent steps. In order to examine whether group work benefits from computer-assistance, we developed CREWSpace. It leverages mobile devices to allow simultaneous interaction with a shared software model. In particular, it implements a digital variant of the CRC method. In this paper, we discuss advantages and disadvantages of the traditional CRC method, briefly introduce CREWSpace along with important implementation details, and focus on a qualitative usability study. Its results suggest that our prototype keeps the advantages of traditional CRC method and compensates many of its weaknesses.