Preliminary design of the redundant software experiment

The goal of the present experiment is to characterize the fault distributions of highly reliable software replicates, constructed using techniques and environments which are similar to those used in comtemporary industrial software facilities. The fault distributions and their effect on the reliability of fault tolerant configurations of the software will be determined through extensive life testing of the replicates against carefully constructed randomly generated test data. Each detected error will be carefully analyzed to provide insight in to their nature and cause. A direct objective is to develop techniques for reducing the intensity of coincident errors, thus increasing the reliability gain which can be achieved with fault tolerance. Data on the reliability gains realized, and the cost of the fault tolerant configurations can be used to design a companion experiment to determine the cost effectiveness of the fault tolerant strategy. Finally, the data and analysis produced by this experiment will be valuable to the software engineering community as a whole because it will provide a useful insight into the nature and cause of hard to find, subtle faults which escape standard software engineering validation techniques and thus persist far into the software life cycle

Musical Program Auralisation: Empirical Studies

Program auralisation aims to communicate information about program state, data, and behaviour using audio. We have argued that music offers many advantages as a communication medium [1]. The CAITLIN system [4, 16, 17, 18] was constructed to provide auralisations within a formal structured musical framework. Pilot studies [4, 16] showed that programmers could infer program structure from auralisations alone. A study was conducted using twenty-two novice programmers to assess a) whether novices could understand the musical auralisations and b) whether the musical experience and knowledge of subjects affected their performance. The results show that novices could interpret the auralisations (with accuracy varying across different levels of abstraction) and that musical knowledge had no significant effect on performance. A second experiment was conducted with another twenty-two novice programmers to study the effects of musical program auralisation on debugging tasks. The experiment aimed to determine whether auralisations would lead to higher bug detection rates. The results indicate that, in certain circumstances, musical auralisations can be used to help locate bugs in programs and that musical skill does not affect the ability to make use of the auralisations. In addition, it the experiment showed that subjective workload increased when the musical auralisations were used

The CAITLIN Auralization System: Hierarchical Leitmotif Design as a Clue to Program Comprehension

Early experiments have suggested that program auralization can convey information about program structure [8]. Languages like Pascal contain classes of construct that are similar in nature allowing hierarchical classification of their features. This taxonomy can be reflected in the design of musical signatures which are used within the CAITLIN program auralization system. Experiments using these hierarchical leitmotifs indicate whether or not their similarities can be put to good use in communicating information about program structure and state

Music and Speech in Auditory Interfaces: When is One Mode More Appropriate Than the Other?

A number of experiments, which have been carried out using non-speech auditory interfaces, are reviewed and the advantages and disadvantages of each are discussed. The possible advantages of using non-speech audio media such as music are discussed – richness of the representations possible, the aesthetic appeal, and the possibilities of such interfaces being able to handle abstraction and consistency across the interface

Teaching Archetypal Design with an Electronic Textbook

How can parallel programming be made tractable for students in high schools and community colleges, to programmers in four-year colleges, to commercial and government employees, to interested independent users learning on their own, and as CASE tools for professional software designers? The computer science community must address this question if the ability of programmers to harness the power of parallel systems is to maintain pace with technology advances forthcoming in parallel systems. This paper addresses some of the issues of bringing parallel programming to the people, ranging from newly developing programmers with little experience on any computer to seasoned programmers of single-processor machines. We aim not only to enable people to use more powerful computers, but also to enable people to use computers more powerfully, by nurturing the techniques that enable them to develop efficient, correct code with relative ease. This paper briefly presents the concept of an Archetype, a software engineering methodology developed at the Caltech for patterns of problem solving, and for providing media for quick reference and natural software reuse. We then describe eText, an interactive multimedia electronic textbook that facilitates the teaching of, navigating through, and referring to Archetypes. Initial experience with Archetypes and the electronic textbook suggests that this approach to teaching parallel programming can aid computer users in the immediate future

ENCOMPASS: A SAGA based environment for the compositon of programs and specifications, appendix A

ENCOMPASS is an example integrated software engineering environment being constructed by the SAGA project. ENCOMPASS supports the specification, design, construction and maintenance of efficient, validated, and verified programs in a modular programming language. The life cycle paradigm, schema of software configurations, and hierarchical library structure used by ENCOMPASS is presented. In ENCOMPASS, the software life cycle is viewed as a sequence of developments, each of which reuses components from the previous ones. Each development proceeds through the phases planning, requirements definition, validation, design, implementation, and system integration. The components in a software system are modeled as entities which have relationships between them. An entity may have different versions and different views of the same project are allowed. The simple entities supported by ENCOMPASS may be combined into modules which may be collected into projects. ENCOMPASS supports multiple programmers and projects using a hierarchical library system containing a workspace for each programmer; a project library for each project, and a global library common to all projects