Generating a Catalog of Unanticipated Schemas in Class Hierarchies using Formal Concept Analysis

International audienceContext: Inheritance is the cornerstone of object-oriented development, supporting conceptual modeling, subtype polymorphism and software reuse. But inheritance can be used in subtle ways that make complex systems hard to understand and extend, due to the presence of implicit dependencies in the inheritance hierarchy. Objective: Although these dependencies often specify well-known schemas (i.e., recurrent design or coding patterns, such as hook and template methods), new unanticipated dependency schemas arise in practice, and can consequently be hard to recognize and detect. Thus, a developer making changes or extensions to an object-oriented system needs to understand these implicit contracts defined by the dependencies between a class and its subclasses, or risk that seemingly innocuous changes break them. Method: To tackle this problem, we have developed an approach based on Formal Concept Analysis. Our FoCARE methodology (Formal Concept Analysis based-Reverse Engineering) identifies undocumented hi- erarchical dependencies in a hierarchy by taking into account the existing structure and behavior of classes and subclasses. Results: We validate our approach by applying it to a large and non-trivial case study, yielding a catalog of Hierarchy Schemas, each one composed of a set of dependencies over methods and attributes in a class hierarchy. We show how the discovered dependency schemas can be used not only to identify good design practices, but also to expose bad smells in design, thereby helping developers in initial reengineering phases to develop a first mental model of a system. Although some of the identified schemas are already documented in existing literature, with our approach based on Formal Concept Analysis (FCA), we are also able to identify previously unidentified schemas

Generating a catalog of unanticipated schemas in class hierarchies using Formal Concept Analysis

Context: Inheritance is the cornerstone of object-oriented development, supporting conceptual modeling, subtype polymorphism and software reuse. But inheritance can be used in subtle ways that make complex systems hard to understand and extend, due to the presence of implicit dependencies in the inheritance hierarchy. Objective: Although these dependencies often specify well-known schemas (i.e., recurrent design or coding patterns, such as hook and template methods), new unanticipated dependency schemas arise in practice, and can consequently be hard to recognize and detect. Thus, a developer making changes or extensions to an object-oriented system needs to understand these implicit contracts defined by the dependencies between a class and its subclasses, or risk that seemingly innocuous changes break them. Method: To tackle this problem, we have developed an approach based on Formal Concept Analysis. Our Formal Concept Analysis based-Reverse Engineering methodology (FoCARE) identifies undocumented hierarchical dependencies in a hierarchy by taking into account the existing structure and behavior of classes and subclasses. Results: We validate our approach by applying it to a large and non-trivial case study, yielding a catalog of hierarchy schemas, each one composed of a set of dependencies over methods and attributes in a class hierarchy. We show how the discovered dependency schemas can be used not only to identify good design practices, but also to expose bad smells in design, thereby helping developers in initial reengineering phases to develop a first mental model of a system. Although some of the identified schemas are already documented in existing literature, with our approach based on Formal Concept Analysis (FCA), we are also able to identify previously unidentified schemas. Conclusions: FCA is an effective tool because it is an ideal classification mining tool to identify commonalities between software artifacts, and usually these commonalities reveal known and unknown characteristics of the software artifacts. We also show that once a catalog of useful schemas stabilizes after several runs of FoCARE, the added cost of FCA is no longer needed.Laboratorio de Investigación y Formación en Informática AvanzadaComisión de Investigaciones Científicas de la provincia de Buenos Aire

A Catalog of Patterns for Concept Lattice Interpretation in Software Reengineering

International audienceFormal Concept Analysis (FCA) provides an important approach in software reengineering for software understanding, design anomalies detection and correction. However, FCA-based approaches have two problems: (i) they produce lattices that must be interpreted by the user according to his/her understanding of the technique and different elements of the graph; and, (ii) the lattice can rapidly become so big that one is overwhelmed by the mass of information and possibilities. In this paper, we present a catalogue of important patterns in concept lattices, which can allow automating the task of lattice interpretation. The approach helps the reengineer to concentrate on the task of reengineering rather than understanding a complex lattice. We provide interpretation of these patterns in a generalized manner and illustrate them on various contexts constructed from program information of different open-source systems. We also present a tool that allows automated extraction of the patterns from concept lattices

Migrating inheritance-based applications into components

Inheritance is one of the most important object-oriented mechanisms, allowing code reuse and a conceptual hierachical modelling of a given domain. However, as a white-box reuse mechanism, it introduces hidden (implicit) coupling between classes in a hierarchy. This problem makes understanding and maintenance difficult to grasp. Actual approaches (such as Gamma’s) propose object composition over class inheritance as reuse mechanism to obtain better object-oriented design. However the migration of a class-based application (or just some software artifacts) from inheritance to composition paradigms is not trivial. To our knowledge, there are only a few approaches that can deal with this problem, but there is no formal language-independent analysis of a transformation algorithm that guarantees the exact same behavior of a system once the migration strategies have been applied. Thus, this paper presents some initial results in designing a refactoring approach for a class hierarchy by analyzing the dependencies between the classes involved in the inheritance relationship in a class-based system, and how they can be transformed to obtain a better structure of the class hierarchy, focusing on getting components with offered- and required-services in component-based system. Based on this study, our main goal in this approach is to develop a (semi)automatic language-independent algorithm using refactoring-based strategies which allows the user to transform an inheritance relationship between a set of classes into an association between two independent components with well defined interfaces.Presentado en el VIII Workshop Ingeniería de Software (WIS)Red de Universidades con Carreras en Informática (RedUNCI

Working Notes from the 1992 AAAI Workshop on Automating Software Design. Theme: Domain Specific Software Design

The goal of this workshop is to identify different architectural approaches to building domain-specific software design systems and to explore issues unique to domain-specific (vs. general-purpose) software design. Some general issues that cut across the particular software design domain include: (1) knowledge representation, acquisition, and maintenance; (2) specialized software design techniques; and (3) user interaction and user interface

Engines of Order

Over the last decades, and in particular since the widespread adoption of the Internet, encounters with algorithmic procedures for ‘information retrieval’ – the activity of getting some piece of information out of a col-lection or repository of some kind – have become everyday experiences for most people in large parts of the world

The 1993 Goddard Conference on Space Applications of Artificial Intelligence

This publication comprises the papers presented at the 1993 Goddard Conference on Space Applications of Artificial Intelligence held at the NASA/Goddard Space Flight Center, Greenbelt, MD on May 10-13, 1993. The purpose of this annual conference is to provide a forum in which current research and development directed at space applications of artificial intelligence can be presented and discussed

BPMNt : a proposal for flexible process tailoring representation in BPMN /

Business Process Model and Notation (BPMN) is a de-facto standard for business process modeling, which focuses on the representation of the process behavior. However, it can also succeed in representing the behavior of software processes, since they are a type of business process. Although BPMN has been extensively used for modeling processes in different domains, its standard specification does not have any mechanism to support users in activities related to process adaptation (tailoring). Moreover, researches extending BPMN are based on complex consolidated models, which hamper the analysis and maintenance of individual variant process models and are not appropriate for application domains in which process variations are difficult to predict, such as in software development processes. Thus, our objective was to provide a BPMN-compliant extension and associated mechanisms for specifying flexible process tailoring on models produced with this language while ensuring the correctness of adapted process models and explicitly capturing change traces. We have focused our research on the domains of Software Process Engineering (SPE) and Business Process Management (BPM). At last, we evaluated the applicability of the proposal for representing realistic tailoring scenarios in both domains.BPMN (Business Process Model and Notation) é um padrão para modelagem de processos de negócio, que tem seu foco na representação do comportamento de processos. No entanto, ele pode também ser usado para representar o comportamento de processos de software, já que eles são um tipo de processo de negócio. Embora BPMN tem sido extensivamente usado para modelar processos em diferentes domínios, sua especificação padrão não possui nenhum mecanismo para apoiar usuários em atividades relacionadas à adaptação de processos. Pesquisas que estendem o padrão são baseadas em modelos complexos, que dificultam a análise e manutenção de modelos variantes, e não são apropriadas para domínios de aplicação onde variações de processo são difíceis de predizer, como em processos de desenvolvimento de software. Assim, nosso objetivo foi fornecer uma extensão para BPMN, chamada BPMNt, e mecanismos de suporte para especificar, de modo flexível, adaptações em processos modelados com esta linguagem. BPMNt deve também garantir a corretude de modelos adaptados e explicitamente capturar rastros de mudanças realizadas. Essa pesquisa teve como foco os domínios de Engenharia de Processos de Software e Gerenciamento de Processos de Negócio. Por fim, nós avaliamos a aplicabilidade da proposta para representar cenários de adaptação reais em ambos os domínios

Becoming Music Teacher: Music Teacher Identity and Strong Structuration Theory

abstract: Previous researchers documented that music teachers negotiate their identities throughout their career, but none of these studies examined identity negotiation from the perspective of both music teachers and their students. Assuming that music teachers and students negotiate their identities through the same interactions, how do music teachers and students together shape their social context and continually pursue possibilities for who they are becoming? I conducted an instrumental case study to explore the encounters of one veteran orchestra teacher—Steve—with three of his students to understand how they negotiated their identities together and pursued possibilities for who they were becoming. I used strong structuration theory (Stones, 2005) as a theoretical lens to organize and frame my study. Each time Steve assessed students and placed them within the orchestra’s seating hierarchy, he experienced a tension in his identity as a music teacher. To relieve this tension, Steve changed the orchestra seating structure from a hierarchical-ranked structure to a randomized-rotating structure. This allowed him to provide individualized feedback to students as they rotated into the front row without issuing social sanctions. But this structural change also disrupted some of the students’ identities as musicians and the labels they used to position themselves in orchestra. Steve’s insistence that the student sitting in first-chair was the “leader for the day” continued an element of the hierarchical seating that conflicted with the students’ understandings of meritocracy and leadership. Additionally, by decoupling the students’ seating from the playing tests, Steve delegitimized his primary form of assessment. Based on my findings, I discuss implications for music education practice, and music teacher education.Dissertation/ThesisDoctoral Dissertation Music Education 201