Bjørnar Tessem

Approximations for efficient computation in the theory of evidence

Abstract The theory of evidence has become a widely used method for handling uncertainty in intelligent systems. The method has, however, an efficiency problem. To solve this problem there is a need for approximations. In this paper an approximation method in the theory of evidence is presented. Further, it is compared experimentally with Bayesian and consonant approximation methods with regard to the error they make. Depending on parameters and the nature of evidence the experiments show that the new method gives comparatively good results. Properties of the approximation methods for presentation purposes are also discussed.

Interval probability propagation

Abstract Belief networks are tried as a method for propagation of singleton interval probabilities. A convex polytope representation of the interval probabilities is shown to make the problem intractable even for small parameters. A solution to this is to use the interval bounds directly in computations of the propagation algorithm. The algorithm presented leads to approximative results but has the advantage of being polynomial in time. It is shown that the method gives fairly good results.

Human and social factors of software engineering: workshop summary

Software is developed for people and by people. Human and social factors have a very strong impact on the success of software development endeavours and the resulting system. Surprisingly, much of software engineering research in the last decade is technical, quantitative and deemphasizes the people aspect. The workshop on Human and Social Factors in Software Engineering has been picking up on the some of the soft aspects in software development that was highlighted in the early days of software engineering. It also follows a recent trend in the software industry, namely the introduction of agile methods, and provides a scientific perspective on these. Including and combining approaches of software engineering with social science, the workshop looked at software engineering from a number of perspectives, including those of agile methods and communication theory, in order to point out solutions and conditions for human-centred software engineering.

Job satisfaction and motivation in a large agile team

Agile software development processes emphasize team work in small groups as one of the features that contribute to high software quality and knowledge dispersion among developers. Research supports claims that agile methods also lead to higher motivation and job satisfaction among developers. Research in workplace psychology indicates that factors like autonomy, variety, significance, feedback, and ability to complete a whole task are significant factors to ensure satisfaction and motivation among workers. In this case study, we show, through the analysis of semi structured interviews with software developers and business representatives, that large teams continuously adapting the SCRUM methodology are able to ensure these empowering factors, and thus ensure a staff of motivated and satisfied software developers. The study presented is based on data from an agile project involving 70 people (including 30 developers) building a software product for the oil & gas industry.

Locative journalism: Designing a location-dependent news medium for smartphones

This article provides an account of the tensions between locative context-awareness and the act of writing journalistic copy for a mobile application. Based on the field trials of the interdisciplinary LocaNews project, the article discusses locative media’s potential for spatially sensitive news journalism. In 2009 researchers in Norway made a medium design called LocaNews, and tested it out with pre-planned procedures for the two fundamental activities: production and reception. Of those who participated, 12 people worked as journalists, editors, technicians, and they generated 93 journalistic stories that were read and watched by 32 test-users who were interviewed. The present article deals with findings regarding the production of news content, and presents the strategies used to reinterpret the traditional news criteria of journalism to be fit for a GPS-equipped smartphone. First, the article discusses the connection between journalism and cartography, and then introduces the experimental method used for this research. The bulk of the article consists of an evaluation of the experimental attempt at practising location-dependent journalism. It deals with four issues: putting stories on the map, the characteristics of ‘zoom in stories’, the construction of an implied position for the readers, and finally the formulation of news criteria that focus on spatial proximity instead of temporal actuality.

Individual empowerment of agile and non-agile software developers in small teams

Abstract Context Empowerment of employees at work has been known to have a positive impact on job motivation and satisfaction. Software development is a field of knowledge work wherein one should also expect to see these effects, and the idea of empowerment has become particularly visible in agile methodologies, in which proponents emphasise team empowerment and individual control of the work activities as a central concern. Objective This research aims to get a better understanding of how empowerment is enabled in software development teams, both agile and non-agile, to identify differences in empowering practices and levels of individual empowerment. Method Twenty-five interviews with agile and non-agile developers from Norway and Canada on decision making and empowerment are analysed. The analysis is conducted using a conceptual model with categories for involvement, structural empowerment and psychological empowerment. Results Both kinds of development organisations are highly empowered and they are similar in most aspects relating to empowerment. However, there is a distinction in the sense that agile developers have more possibilities to select work tasks and influence the priorities in a development project due to team empowerment. Agile developers seem to put a higher emphasis on the value of information in decision making, and have more prescribed activities to enable low-cost information flow. More power is obtained through the achievement of managing roles for the non-agile developers who show interest and are rich in initiatives. Conclusion Agile developers have a higher sense of being able to impact the organisation than non-agile developers and have information channels that is significantly differently from non-agile developers. For non-agile teams, higher empowerment can be obtained by systematically applying low-cost participative decision making practices in the manager–developer relation and among peer developers. For agile teams, it is essential to more rigorously follow the empowering practices already established.

Human and social factors of software engineering

No abstract available

Analogy and complex software modeling

Abstract Research on software reuse has to a large extent focused on lowlevel software components. However, facilitating genuinely efficient reuse of software requires knowledge of a previous situation in which a system behaves in some deep and fundamental sense analogically to the system to be constructed. Achieving this goal can only be done by reuse at the highest level of description, that is, at the analysis level. In this paper we present the ROSA project, where we study how to implement support for reuse of analysis models by analogy. The focus is on how to retrieve analogies, how to map them, and how to transfer knowledge from one problem situation to a new problem situation. We base our presentation on work in cognitive psychology, cognitive science, artificial intelligence, and software reuse.

Cooperation between developers and operations in software engineering projects

In this paper we discuss how the cooperation between developers and operations staff is practiced. We have analyzed data collected from a focus group of experienced software engineers and project managers, as well as interviews from two case studies. Our position is that well performed cooperation between the development team and the operations team is crucial for successful deployment and operations of a new or extensively revised software system. The data shows that cooperation can be improved in several development activities like requirements engineering, system design, documentation, testing, training, and deployment planning. Likely consequences of poor cooperation in these activities are lower productivity in development and operations, as well as unsatisfied users.

Retrieval of Java Classes for Case-Based Reuse

Rapid prototyping in object-oriented programming requires effective retrieval of reusable classes. This paper describes the methods used in the retrieval phase of a case-based component in a prototyping tool for the Java programming language. The case-based tool aids in class retrieval and reuse. Java has a reflective ability in the sense that classes may be asked for their methods, fields, constructors, and other information. We use this information to automatically generate features used to index the Java classes. We use both the reflected information, and knowledge inferred from that information. We describe the retrieval algorithm used in the case-based tool, and show some example runs.