@article{ReinRamsonLinckeetal.2017,
  author    = {Rein, Patrick and Ramson, Stefan and Lincke, Jens and Felgentreff, Tim and Hirschfeld, Robert},
  title     = {Group-Based Behavior Adaptation Mechanisms in Object-Oriented Systems},
  series = {IEEE software},
  volume    = {34},
  journal   = {IEEE software},
  number    = {6},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Los Alamitos},
  issn      = {0740-7459},
  doi       = {10.1109/MS.2017.4121224},
  pages     = {78 -- 82},
  year      = {2017},
  abstract  = {Dynamic and distributed systems require behavior adaptations for groups of objects. Group-based behavior adaptation mechanisms scope adaptations to objects matching conditions beyond class membership. The specification of groups can be explicit or implicit.},
  language  = {en}
}
@article{HirschfeldKawarnura2006,
  author    = {Hirschfeld, Robert and Kawarnura, Katsuya},
  title     = {Dynamic service adaptation},
  series = {Software : practice \& experience},
  volume    = {36},
  journal   = {Software : practice \& experience},
  number    = {11-12},
  publisher = {Wiley},
  address   = {Chichester},
  issn      = {0038-0644},
  doi       = {10.1002/spe.766},
  pages     = {1115 -- 1131},
  year      = {2006},
  abstract  = {Change can be observed in our environment and in the technology we build. While changes in the environment happen continuously and implicitly, our technology has to be kept in sync with the changing world around it. Although we can prepare for some of the changes for most of them we cannot. This is especially true for next-generation mobile communication systems that are expected to support the creation of a ubiquitous society where virtually everything is connected and made available within an organic information network. Resources will frequently join or leave the network, new types of media or new combinations of existing types will be used to interact and cooperate, and services will be tailored to preferences and needs of individual customers to better meet their needs. This paper outlines our research in the area of dynamic service adaptation to provide concepts and technologies allowing for such environments. Copyright (C) 2006 John Wiley \& Sons, Ltd.},
  language  = {en}
}
@article{MattisBeckmannReinetal.2022,
  author    = {Mattis, Toni and Beckmann, Tom and Rein, Patrick and Hirschfeld, Robert},
  title     = {First-class concepts},
  series = {Journal of object technology : JOT / ETH Z{\"u}rich, Department of Computer Science},
  volume    = {21},
  journal   = {Journal of object technology : JOT / ETH Z{\"u}rich, Department of Computer Science},
  number    = {2},
  publisher = {ETH Z{\"u}rich, Department of Computer Science},
  address   = {Z{\"u}rich},
  issn      = {1660-1769},
  doi       = {10.5381/jot.2022.21.2.a6},
  pages     = {1 -- 15},
  year      = {2022},
  abstract  = {Ideally, programs are partitioned into independently maintainable and understandable modules. As a system grows, its architecture gradually loses the capability to accommodate new concepts in a modular way. While refactoring is expensive and not always possible, and the programming language might lack dedicated primary language constructs to express certain cross-cutting concerns, programmers are still able to explain and delineate convoluted concepts through secondary means: code comments, use of whitespace and arrangement of code, documentation, or communicating tacit knowledge. <br /> Secondary constructs are easy to change and provide high flexibility in communicating cross-cutting concerns and other concepts among programmers. However, such secondary constructs usually have no reified representation that can be explored and manipulated as first-class entities through the programming environment. <br /> In this exploratory work, we discuss novel ways to express a wide range of concepts, including cross-cutting concerns, patterns, and lifecycle artifacts independently of the dominant decomposition imposed by an existing architecture. We propose the representation of concepts as first-class objects inside the programming environment that retain the capability to change as easily as code comments. We explore new tools that allow programmers to view, navigate, and change programs based on conceptual perspectives. In a small case study, we demonstrate how such views can be created and how the programming experience changes from draining programmers' attention by stretching it across multiple modules toward focusing it on cohesively presented concepts. Our designs are geared toward facilitating multiple secondary perspectives on a system to co-exist in symbiosis with the original architecture, hence making it easier to explore, understand, and explain complex contexts and narratives that are hard or impossible to express using primary modularity constructs.},
  language  = {en}
}
@article{PerscheidSiegmundTaeumeletal.2017,
  author    = {Perscheid, Michael and Siegmund, Benjamin and Taeumel, Marcel and Hirschfeld, Robert},
  title     = {Studying the advancement in debugging practice of professional software developers},
  series = {Software Quality Journal},
  volume    = {25},
  journal   = {Software Quality Journal},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0963-9314},
  doi       = {10.1007/s11219-015-9294-2},
  pages     = {83 -- 110},
  year      = {2017},
  abstract  = {In 1997, Henry Lieberman stated that debugging is the dirty little secret of computer science. Since then, several promising debugging technologies have been developed such as back-in-time debuggers and automatic fault localization methods. However, the last study about the state-of-the-art in debugging is still more than 15 years old and so it is not clear whether these new approaches have been applied in practice or not. For that reason, we investigate the current state of debugging in a comprehensive study. First, we review the available literature and learn about current approaches and study results. Second, we observe several professional developers while debugging and interview them about their experiences. Third, we create a questionnaire that serves as the basis for a larger online debugging survey. Based on these results, we present new insights into debugging practice that help to suggest new directions for future research.},
  language  = {en}
}
@article{FelgentreffPerscheidHirschfeld2017,
  author    = {Felgentreff, Tim and Perscheid, Michael and Hirschfeld, Robert},
  title     = {Implementing record and refinement for debugging timing-dependent communication},
  series = {Science of computer programming},
  volume    = {134},
  journal   = {Science of computer programming},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0167-6423},
  doi       = {10.1016/j.scico.2015.11.006},
  pages     = {4 -- 18},
  year      = {2017},
  abstract  = {Distributed applications are hard to debug because timing-dependent network communication is a source of non-deterministic behavior. Current approaches to debug non deterministic failures include post-mortem debugging as well as record and replay. However, the first impairs system performance to gather data, whereas the latter requires developers to understand the timing-dependent communication at a lower level of abstraction than they develop at. Furthermore, both approaches require intrusive core library modifications to gather data from live systems. In this paper, we present the Peek-At-Talk debugger for investigating non-deterministic failures with low overhead in a systematic, top-down method, with a particular focus on tool-building issues in the following areas: First, we show how our debugging framework Path Tools guides developers from failures to their root causes and gathers run-time data with low overhead. Second, we present Peek-At-Talk, an extension to our Path Tools framework to record non-deterministic communication and refine behavioral data that connects source code with network events. Finally, we scope changes to the core library to record network communication without impacting other network applications.},
  language  = {en}
}
@article{ReinTaeumelHirschfeld2017,
  author    = {Rein, Patrick and Taeumel, Marcel and Hirschfeld, Robert},
  title     = {Making the domain tangible},
  series = {Design Thinking Research},
  journal   = {Design Thinking Research},
  publisher = {Springer},
  address   = {New York},
  isbn      = {978-3-319-60967-6},
  doi       = {10.1007/978-3-319-60967-6_9},
  pages     = {171 -- 194},
  year      = {2017},
  abstract  = {Programmers collaborate continuously with domain experts to explore the problem space and to shape a solution that fits the users' needs. In doing so, all parties develop a shared vocabulary, which is above all a list of named concepts and their relationships to each other. Nowadays, many programmers favor object-oriented programming because it allows them to directly represent real-world concepts and interactions from the vocabulary as code. However, when existing domain data is not yet represented as objects, it becomes a challenge to initially bring existing domain data into object-oriented systems and to keep the source code readable. While source code might be comprehensible to programmers, domain experts can struggle, given their non-programming background. We present a new approach to provide a mapping of existing data sources into the object-oriented programming environment. We support keeping the code of the domain model compact and readable while adding implicit means to access external information as internal domain objects. This should encourage programmers to explore different ways to build the software system quickly. Eventually, our approach fosters communication with the domain experts, especially at the beginning of a project. When the details in the problem space are not yet clear, the source code provides a valuable, tangible communication artifact.},
  language  = {en}
}
@article{SteinertCassouHirschfeld2013,
  author    = {Steinert, Bastian and Cassou, Damien and Hirschfeld, Robert},
  title     = {CoExist overcoming aversion to change preserving immediate access to source code and run-time information of previous development states},
  series = {ACM SIGPLAN notices},
  volume    = {48},
  journal   = {ACM SIGPLAN notices},
  number    = {2},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  issn      = {0362-1340},
  doi       = {10.1145/2480360.2384591},
  pages     = {107 -- 117},
  year      = {2013},
  abstract  = {Programmers make many changes to the program to eventually find a good solution for a given task. In this course of change, every intermediate development state can of value, when, for example, a promising ideas suddenly turn out inappropriate or the interplay of objects turns out more complex than initially expected before making changes. Programmers would benefit from tool support that provides immediate access to source code and run-time of previous development states of interest. We present IDE extensions, implemented for Squeak/Smalltalk, to preserve, retrieve, and work with this information. With such tool support, programmers can work without worries because they can rely on tools that help them with whatever their explorations will reveal. They no longer have to follow certain best practices only to avoid undesired consequences of changing code.},
  language  = {en}
}
@article{HauptAdamsTimbermontetal.2009,
  author    = {Haupt, Michael and Adams, Bram and Timbermont, Stijn and Gibbs, Celina and Coady, Yvonne and Hirschfeld, Robert},
  title     = {Disentangling virtual machine architecture},
  issn      = {1751-8806},
  doi       = {10.1049/iet-sen.2007.0121},
  year      = {2009},
  abstract  = {Virtual machine (VM) implementations are made of intricately intertwined subsystems, interacting largely through implicit dependencies. As the degree of crosscutting present in VMs is very high, VM implementations exhibit significant internal complexity. This study proposes an architecture approach for VMs that regards a VM as a composite of service modules coordinated through explicit bidirectional interfaces. Aspect-oriented programming techniques are used to establish these interfaces, to coordinate module interaction, and to declaratively express concrete VM architectures. A VM architecture description language is presented in a case study, illustrating the application of the proposed architectural principles.},
  language  = {en}
}
@article{SteinertHirschfeld2012,
  author    = {Steinert, Bastian and Hirschfeld, Robert},
  title     = {Applying design knowledge to programming},
  year      = {2012},
  language  = {en}
}
@article{HirschfeldSteinertLincke2011,
  author    = {Hirschfeld, Robert and Steinert, Bastian and Lincke, Jens},
  title     = {Agile software development in virtual collaboration environments},
  isbn      = {978-3-642-13756-3},
  year      = {2011},
  language  = {en}
}