05 Fakultät Informatik, Elektrotechnik und Informationstechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6

Browse

Filters

Settings

Publication Type: search.filters.UBSTyp.KonferenzbeitragInstitute: search.filters.UBSInstitut.Fakultätsübergreifend / Sonstige EinrichtungSubject: search.filters.subject.004

Search Results

Now showing 1 - 10 of 21
  • Thumbnail Image
    ItemOpen Access
    Empirical research plan: effects of sketching on program comprehension
    (2016) Baltes, Sebastian; Wagner, Stefan
    Sketching is an important means of communication in software engineering practice. Yet, there is little research investigating the use of sketches. We want to contribute a better understanding of sketching, in particular its use during program comprehension. We propose a controlled experiment to investigate the effectiveness and efficiency of program comprehension with the support of sketches as well as what sketches are used in what way.
  • Thumbnail Image
    ItemOpen Access
    A comprehensive safety engineering approach for software-intensive systems based on STPA
    (2015) Abdulkhaleq, Asim; Wagner, Stefan; Leveson, Nancy
    Formal verification and testing are complementary approaches which are used in the development process to verify the functional correctness of software. However, the correctness of software cannot ensure the safe operation of safety-critical software systems. The software must be verified against its safety requirements which are identified by safety analysis, to ensure that potential hazardous causes cannot occur. The complexity of software makes defining appropriate software safety requirements with traditional safety analysis techniques difficult. STPA (Systems-Theoretic Processes Analysis) is a unique safety analysis approach that has been developed to identify system hazards, including the software-related hazards. This paper presents a comprehensive safety engineering approach based on STPA, including software testing and model checking approaches for the purpose of developing safe software. The proposed approach can be embedded within a defined software engineering process or applied to existing software systems, allow software and safety engineers integrate the analysis of software risks with their verification. The application of the proposed approach is illustrated with an automotive software controller.
  • Thumbnail Image
    ItemOpen Access
    Modelling the quality economics of defect-detection techniques
    (2006) Wagner, Stefan
    There are various ways to evaluate defect-detection techniques. However, for a comprehensive evaluation the only possibility is to reduce all influencing factors to costs. There are already some models and metrics for the cost of quality that can be used in that context. These models allow the structuring of the costs but do not show all influencing factors and their relationships. This paper proposes an analytical model for the economics of defect-detection techniques that can be used for analysis and optimisation of the usage of such techniques. In particular we analyse the sensitivity of the model and how the model can be applied in practice.
  • Thumbnail Image
    ItemOpen Access
    SalChartQA: question-driven saliency on information visualisations
    (2024) Wang, Yao; Wang, Weitian; Abdelhafez, Abdullah; Elfares, Mayar; Hu, Zhiming; Bâce, Mihai; Bulling, Andreas
    Understanding the link between visual attention and user’s needs when visually exploring information visualisations is under-explored due to a lack of large and diverse datasets to facilitate these analyses. To fill this gap, we introduce SalChartQA - a novel crowd-sourced dataset that uses the BubbleView interface as a proxy for human gaze and a question-answering (QA) paradigm to induce different information needs in users. SalChartQA contains 74,340 answers to 6,000 questions on 3,000 visualisations. Informed by our analyses demonstrating the tight correlation between the question and visual saliency, we propose the first computational method to predict question-driven saliency on information visualisations. Our method outperforms state-of-the-art saliency models, improving several metrics, such as the correlation coefficient and the Kullback-Leibler divergence. These results show the importance of information needs for shaping attention behaviour and paving the way for new applications, such as task-driven optimisation of visualisations or explainable AI in chart question-answering.
  • Thumbnail Image
    ItemOpen Access
    Software quality models : purposes, usage scenarios and requirements
    (2009) Deißenböck, Florian; Juergens, Elmar; Lochmann, Klaus; Wagner, Stefan
    Software quality models are a well-accepted means to support quality management of software systems. Over the last 30 years, a multitude of quality models have been proposed and applied with varying degrees of success. Despite successes and standardisation efforts, quality models are still being criticised, as their application in practice exhibits various problems. To some extent, this criticism is caused by an unclear definition of what quality models are and which purposes they serve. Beyond this, there is a lack of explicitly stated requirements for quality models with respect to their intended mode of application. To remedy this, this paper describes purposes and usage scenarios of quality models and, based on the literature and experiences from the authors, collects critique of existing models. From this, general requirements for quality models are derived. The requirements can be used to support the evaluation of existing quality models for a given context or to guide further quality model development.
  • Thumbnail Image
    ItemOpen Access
    The Quamoco product quality modelling and assessment approach
    (2012) Wagner, Stefan; Lochmann, Klaus; Heinemann, Lars; Kläs, Michael; Trendowicz, Adam; Plösch, Reinhold; Seidl, Andreas; Goeb, Andreas; Streit, Jonathan
    Published software quality models either provide abstract quality attributes or concrete quality assessments. There are no models that seamlessly integrate both aspects. In the project Quamoco, we built a comprehensive approach with the aim to close this gap. For this, we developed in several iterations a meta quality model specifying general concepts, a quality base model covering the most important quality factors and a quality assessment approach. The meta model introduces the new concept of a product factor, which bridges the gap between concrete measurements and abstract quality aspects. Product factors have measures and instruments to operationalise quality by measurements from manual inspection and tool analysis. The base model uses the ISO 25010 quality attributes, which we refine by 200 factors and 600 measures for Java and C# systems. We found in several empirical validations that the assessment results fit to the expectations of experts for the corresponding systems. The empirical analyses also showed that several of the correlations are statistically significant and that the maintainability part of the base model has the highest correlation, which fits to the fact that this part is the most comprehensive. Although we still see room for extending and improving the base model, it shows a high correspondence with expert opinions and hence is able to form the basis for repeatable and understandable quality assessments in practice.
  • Thumbnail Image
    ItemOpen Access
    Mining valence, arousal, and dominance - possibilities for detecting burnout and productivity?
    (2016) Mäntylä, Mika; Adams, Bram; Destefanis, Giuseppe; Graziotin, Daniel; Ortu, Marco
    Similar to other industries, the software engineering domain is plagued by psychological diseases such as burnout, which lead developers to lose interest, exhibit lower activity and/or feel powerless. Prevention is essential for such diseases, which in turn requires early identification of symptoms. The emotional dimensions of Valence, Arousal and Dominance (VAD) are able to derive a person's interest (attraction), level of activation and perceived level of control for a particular situation from textual communication, such as emails. As an initial step towards identifying symptoms of productivity loss in software engineering, this paper explores the VAD metrics and their properties on 700,000 Jira issue reports containing over 2,000,000 comments, since issue reports keep track of a developer's progress on addressing bugs or new features. Using a general-purpose lexicon of 14,000 English words with known VAD scores, our results show that issue reports of different type (e.g., Feature Request vs. Bug) have a fair variation of Valence, while increase in issue priority (e.g., from Minor to Critical) typically increases Arousal. Furthermore, we show that as an issue's resolution time increases, so does the arousal of the individual the issue is assigned to. Finally, the resolution of an issue increases valence, especially for the issue Reporter and for quickly addressed issues. The existence of such relations between VAD and issue report activities shows promise that text mining in the future could offer an alternative way for work health assessment surveys.
  • Thumbnail Image
    ItemOpen Access
    Interdisciplinary system courses - teaching agile systems engineering
    (2019) Seitz, Andreas; Avezum, Mariana; Bruegge, Bernd; Wagner, Stefan
    With the advent of technologies like the Internet of Things, Industry 4.0 and Cyber-Physical Systems, many software engineering courses turn into system engineering courses. Recent advances in technologies such as 3D printing and low-cost micro controllers enable to teach agile hard- and software co-design in system engineering courses. In this paper, we describe Interdisciplinary System Courses (ISC) - a teaching approach based on interdisciplinary projects, light-weight agile techniques and solving real problems by integrating industry customers. We describe our experiences from an exploratory case study where we applied ISC in a two-week international summer school with a customer from the aerospace industry. We derive a set of hypotheses on the effects of ISC.
  • Thumbnail Image
    ItemOpen Access
    Mouse2Vec: learning reusable semantic representations of mouse behaviour
    (2024) Zhang, Guanhua; Hu, Zhiming; Bâce, Mihai; Bulling, Andreas
    The mouse is a pervasive input device used for a wide range of interactive applications. However, computational modelling of mouse behaviour typically requires time-consuming design and extraction of handcrafted features, or approaches that are application-specific. We instead propose Mouse2Vec - a novel self-supervised method designed to learn semantic representations of mouse behaviour that are reusable across users and applications. Mouse2Vec uses a Transformer-based encoder-decoder architecture, which is specifically geared for mouse data: During pretraining, the encoder learns an embedding of input mouse trajectories while the decoder reconstructs the input and simultaneously detects mouse click events. We show that the representations learned by our method can identify interpretable mouse behaviour clusters and retrieve similar mouse trajectories. We also demonstrate on three sample downstream tasks that the representations can be practically used to augment mouse data for training supervised methods and serve as an effective feature extractor.
  • Thumbnail Image
    ItemOpen Access
    Naming the pain in requirements engineering: design of a global family of surveys and first results from Germany
    (2013) Méndez Fernández, Daniel; Wagner, Stefan
    Context: For many years, we have observed industry struggling in defining a high quality requirements engineering (RE) and researchers trying to understand industrial expectations and problems. Although we are investigating the discipline with a plethora of empirical studies, those studies either concentrate on validating specific methods or on single companies or countries. Therefore, they allow only for limited empirical generalisations. Objective: To lay an empirical and generalisable foundation about the state of the practice in RE, we aim at a series of open and reproducible surveys that allow us to steer future research in a problem-driven manner. Method: We designed a globally distributed family of surveys in joint collaborations with different researchers from different countries. The instrument is based on an initial theory inferred from available studies. As a long-term goal, the survey will be regularly replicated to manifest a clear understanding on the status quo and practical needs in RE. In this paper, we present the design of the family of surveys and first results of its start in Germany. Results: Our first results contain responses from 30 German companies. The results are not yet generalisable, but already indicate several trends and problems. For instance, a commonly stated problem respondents see in their company standards are artefacts being underrepresented, and important problems they experience in their projects are incomplete and inconsistent requirements. Conclusion: The results suggest that the survey design and instrument are well-suited to be replicated and, thereby, to create a generalisable empirical basis of RE in practice.