Roland T. Mittermeir

A survey of software reuse libraries

The study of storage and retrieval methods of software assets in software libraries gives rise to a number of paradoxes: While this subject has been under investigation for nearly two decades, it still remains an active area of research in software reuse and software engineering; this can be explained by the observation that new technologies (such as the internet, the world wide web, object-;oriented programming) keep opening new opportunities for better asset packaging, better library organizations, and larger scale libraries – thereby posing new technical challenges. Also, while many sophisticated solutions have been proposed to this problem, the state of the practice in software reuse is characterized by the use of ad-;hoc, low-;tech methods; this can be explained by the observation that most existing solutions are either too ineffective to be useful or too intractable to be usable. Finally, while it is difficult to imagine a successful software reuse program without a sophisticated, well-;tuned, systematic procedure for software component storage and retrieval, it seems many successful software reuse experiments rely on trivial methods of component storage and retrieval; this can be explained by the observation that, in the current state of the practice, software libraries are not the bottleneck of the software reuse process. This paper presents a survey of methods of storage and retrieval of software assets in software libraries. In addition to a review of existing research efforts, the paper makes two contributions. First, a definition of (presumably) orthogonal attributes of storage and retrieval methods; these attributes are used, in turn, to classify existing methods into six broad classes. Second, a definition of (presumably) orthogonal assessment criteria, which include technical, managerial and human factors; these criteria afford us an exhaustive and uniform basis for assessing and comparing individual methods and classes of methods.

Storing and retrieving software components: a refinement based system

Software reuse poses a number of challenges, ranging from managerial to technical - not least of these is the problem of storing and retrieving software components in a time efficient manner. This paper presents the design and implementation of an automated software repository, where software components can be automatically stored and retrieved. This repository is based on a formal representation of programs and their specifications, as well as a refinement ordering of these specifications.<<ETX>>

Finding high-level structures in spreadsheet programs

Spreadsheets are a common tool in end-user programming, but even while important decisions are based on spreadsheet computations, spreadsheets are poorly documented software and the differences between simple one-shot computations and large, long-living sheets are not well understood. Like other software, production spreadsheets are subject to repeated maintenance cycles. Consequently, as with conventional software, short maintenance cycles and poor documentation tend to decrease their quality. We introduce an approach to help maintainers understand the structure of large spreadsheets as well as to zoom into certain parts of the spreadsheet. To cope with large sheets, our approach features two levels of abstraction: logical areas and semantic classes. These abstractions are based on different degrees of relatedness of cells according to the formulas they contain.

Computer science/informatics in secondary education

Computer Science (CS) Education research, specifically when focusing on secondary education, faces the difficulty of regionally differing political, legal, or curricular constraints. To date, many different studies exist that document the specific regional situations of teaching CS in secondary schools. This ITiCSE working group report documents the process of collecting, evaluating, and integrating research findings about CS in secondary schools from different countries. As an outcome, it presents a category system (Darmstadt Model), as a first step towards a framework that sup-ports future research activities in this field and that supports the transfer of results between researchers and teachers in CS education (CSE) across regional or national boundaries. Exemplary application of the Darmstadt model shows in several important categories how different the situation of CSE in secondary education in various countries can be. The Darmstadt Model (DM) is now ready for discussion and suggestions for improvement by the CSE-community.

Towards Incremental Fuzzy Classifiers

Fuzzy classification systems (FCS) are traditionally built from observations (data points) in an off-line one shot-experiment. Once the learning phase is exhausted, the classifier is no more capable to learn further knowledge from new observations nor is it able to update itself in the future. This paper investigates the problem of incremental learning in the context of FCS. It shows how, in contrast to off-line or batch learning, incremental learning infers knowledge in the form of fuzzy rules from data that evolves over time. To accommodate incremental learning, appropriate mechanisms are applied in all steps of the FCS construction: (1) Incremental supervised clustering to generate granules in a progressive manner, (2) Systematic and automatic update of fuzzy partitions, (3) Incremental feature selection using an incremental version of Fisher’s interclass separability criterion. The effect of incrementality on various aspects is demonstrated via a numerical evaluation.

A commonsense management model

A description is given of a process-management model, called cosmos, which combines the best of existing models by incorporating three perspectives: activity, communication, and infrastructure. Cosmos is designed to manage a large software system from beginning to end. Current problems in system development are reviewed, and the principles on which cosmos is based are outlined. The reasons for using such a three-dimensional model are examined. The use of cosmos is described.<<ETX>>

Software Bases for the Flexible Composition of Application Systems

In various application areas, classes of computer programs can be identified such that each program belonging to a class, can be considered as a special variant of a generic program.

Perspectives and Visions of Computer Science Education in Primary and Secondary (K-12) Schools

In view of the recent developments in many countries, for example, in the USA and in the UK, it appears that computer science education (CSE) in primary or secondary schools (K-12) has reached a significant turning point, shifting its focus from ICT-oriented to rigorous computer science concepts. The goal of this special issue is to offer a publication platform for soundly based in-depth experiences that have been made around the world with concepts, approaches, or initiatives that aim at supporting this shift. For this purpose, the article format was kept as large as possible, enabling the authors to explain many facets of their concepts and experiences in detail. Regarding the structure of the articles, we had encouraged the authors to lean on the Darmstadt Model, a category system that was developed to support the development, improvement, and investigation of K-12 CSE across regional or national boundaries. This model could serve as a unifying framework that might provide a proper structure for a well-founded critical discussion about the future of K-12 CSE. Curriculum designers or policy stakeholders, who have to decide, which approach an upcoming national initiative should follow, could benefit from this discussion as well as researchers who are investigating K12 CSE in any regard. With this goal in mind, we have selected six extensive and two short case studies from the UK, New Zealand, USA/Israel, France, Sweden, Georgia (USA), Russia, and Italy that provide an in-depth analysis of K-12 CSE in their respective country or state.

Showing Core-Concepts of Informatics to Kids and Their Teachers

Computer science education in schools focuses in many countries on the use of IT-equipment rather than on foundational concepts informatics of fers. Although this is partly justified by immediate use of IT-literacy of pupils, it is as much due to the lack of deeper knowledge in computing on the part of teachers. But this application-based instruction distorts the pupils percep tion of informatics and thus, leads to lack of interest in informatics related professions. This paper reports on a project that shows both, pupils and teachers, some principles of informatics in order to make the students curious to learn more about it and showing both groups that informatics offers more than its applications. It also shows teachers that concepts of informatics are not too difficult to teach and to grasp.

Publication productivity and professional position: Cross-national evidence on the role of organizations

Studies of strafication in science have increasingly accepted the idea that science is a highly stratified and elitist system with skewed distributions of productivity and rewards. Attempts to explain the higher productivity of higher status scientists by pointing to their greater ease of publication as far as acceptance of their work by journals and publishers is concerned were not supported by the data in some recent studies. If status in general does not confer greater ease of publication the present paper argues that position within a research organization does confer greater ease of author — or co-authorship — and this is the major explanatory variable accounting for productivity differences within research laboratories as far as quantity of articles (and books) is concerned. upward moves in a laboratorys formal or informal position hierarchy are associated with a change of a scientists research involvement from goal executing to goal setting functions as well as with an increasing access to scientific manpower and project money. Goal setting tasks provide for a significant reduction of time-expenditures in research necessary to assure that the scientist is identified with the research results; consequently, they allow for an involvement in more research tasks than originally. Equivalently, resources in scientific manpower and project money act as a multiplying element as far as quantity of output is concerned.