Understanding replication of experiments in software engineering: a classification

Context: Replication plays an important role in experimental disciplines. There are still many uncertain- ties about how to proceed with replications of SE experiments. Should replicators reuse the baseline experiment materials? How much liaison should there be among the original and replicating experiment- ers, if any? What elements of the experimental configuration can be changed for the experiment to be considered a replication rather than a new experiment? Objective: To improve our understanding of SE experiment replication, in this work we propose a classi- fication which is intend to provide experimenters with guidance about what types of replication they can perform. Method: The research approach followed is structured according to the following activities: (1) a litera- ture review of experiment replication in SE and in other disciplines, (2) identification of typical elements that compose an experimental configuration, (3) identification of different replications purposes and (4) development of a classification of experiment replications for SE. Results: We propose a classification of replications which provides experimenters in SE with guidance about what changes can they make in a replication and, based on these, what verification purposes such a replication can serve. The proposed classification helped to accommodate opposing views within a broader framework, it is capable of accounting for less similar replications to more similar ones regarding the baseline experiment. Conclusion: The aim of replication is to verify results, but different types of replication serve special ver- ification purposes and afford different degrees of change. Each replication type helps to discover partic- ular experimental conditions that might influence the results. The proposed classification can be used to identify changes in a replication and, based on these, understand the level of verification

A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing

Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this paper, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration. Through this taxonomy, we aim to categorise existing systems to better understand their goals and their methodology. This would help evaluate their applicability for solving similar problems. This taxonomy also provides a "gap analysis" of this area through which researchers can potentially identify new issues for investigation. Finally, we hope that the proposed taxonomy and mapping also helps to provide an easy way for new practitioners to understand this complex area of research.Comment: 46 pages, 16 figures, Technical Repor

The Globe Infrastructure Directory Service

To implement adaptive replication strategies for Web documents, we have developed a wide area resource management system. This system allows servers to be managed on a local and global level. On a local level the system manages information about the resources and services provided by the servers, while on a global level the system allows servers to be searched for, added to, and removed from the system. As part of the system, and also in order to implement adaptive replication strategies, we introduce a hierarchical location representation for network elements such as servers, objects, and clients. This location representation allows us to easily and efficiently find and group network elements based on their location in a worldwide network. Our resource management system can be implemented using standard Internet technologies and has a broader range of applications besides making adaptive replication strategies possible for Web documents

Building Age-Friendly Community: Notes from the Field

Building age-friendly communities is a global as well as a national concern. The purpose of this paper is to explore fundamental tensions underlying the formulation of age-friendly goals and their implementation, based on a review of age-friendly projects and reflections on the journey towards age friendliness in one state (Rhode Island). The authors conducted a comprehensive investigation of the relevant literature on previous age-friendly initiatives, which included case studies of individual projects, meta-analyses of age-friendly work, and educational toolkits for promoting age-friendly community. They also collected original data from ten focus groups with older adults, interviews with key informant service providers, surveys of older adults and observational environmental audits. Through this multi-faceted approach, they identified recurrent questions often not overtly addressed in building livable communities, despite their being central to decisions made in age-friendly projects. This paper focuses on six questions: Age friendliness for whom? Older adults viewed as a burden or a benefit? Age friendliness by or for older adults? Is age friendliness affordable? Should the target be the aged overall or the needy aged in particular? Should interventions aim to change people or places? The Aging in Community Report, (prepared by the authors and submitted to Rhode Island’s General Assembly), reflected decisions made—albeit sometimes inadvertently—in response to these questions. It showed that priority was given to age friendliness over livability, assistance to vulnerable, older adults was given precedence over helping the entire older population, and top-down interventions were emphasized more than grass-roots endeavors. Its recommendations were geared to leveraging or modestly increasing existing resources to better serve older adults and enhancing opportunities for older adults to contribute to their community. Following the release of the report, the focus shifted from modifications of the environment to facilitating changes in individual behavior to optimize person-environment fit