Designing software for children

This brief paper describes the considerations behind the design and use of a programming language and editor for use by children of primary school age.     

Designing free software samples: a game theoretic approach

We develop a vertical differentiation game-theoretic model that addresses the issue of designing free software samples (shareware) for attaining follow-on sales. When shareware can be reinstalled, cannibalization of sales of the commercial product may ensue. We analyze the optimal design of free software according to two characteristics: the evaluation period allotted for sampling (potentially renewable) and the proportion of features included in the sample. We introduce a new software classification scheme based on the characteristics of the sample that aid consumer learning. We find that the optimal combination of features and trial time greatly depends on the category of software within the classification scheme. Under alternative learning scenarios, we show that the monopolist may be better off not suppressing potential shareware reinstallation.

A software architecture framework for on-line option pricing

The problem of growing computational complexity in the finance industry demands manageable, high-speed and real-time solutions in solving complex mathematical problems such as option pricing. In current option trading scenarios, determining a fair price for options “any time” and “anywhere” has become vital yet difficult computational problem. In this study, we have designed, implemented, and deployed an architecture for pricing options on-line using a hand-held device that is J2ME-based Mobile computing-enabled and is assisted by web mining tools. In our architecture, the client is a MIDP user interface, and the back end servlet runs on a standalone server bound to a known port address. In addition, the server uses table-mining techniques to mine real-time data from reliable web sources upon the mobile trader’s directive. The server performs all computations required for pricing options since mobile devices have limited battery power, low bandwidth, and low memory. We have parallelized and implemented various computational techniques such as binomial lattice and finite differencing. To the best of our knowledge, this is one of the first studies that facilitate the mobile-enabled-trader to compute the price of an option in ubiquitous fashion. This architecture aims at providing the trader with various computational techniques to avail (to provide results from approximate to accurate results) while on-the-go and to make important and effective trading decisions using the results that will ensure higher returns on investments in options.

Classification with reject option for software defect prediction

ContextSoftware defect prediction (SDP) is an important task in software engineering. Along with estimating the number of defects remaining in software systems and discovering defect associations, classifying the defect-proneness of software modules plays an important role in software defect prediction. Several machine-learning methods have been applied to handle the defect-proneness of software modules as a classification problem. This type of “yes” or “no” decision is an important drawback in the decision-making process and if not precise may lead to misclassifications. To the best of our knowledge, existing approaches rely on fully automated module classification and do not provide a way to incorporate extra knowledge during the classification process. This knowledge can be helpful in avoiding misclassifications in cases where system modules cannot be classified in a reliable way.ObjectiveWe seek to develop a SDP method that (i) incorporates a reject option in the classifier to improve the reliability in the decision-making process; and (ii) makes it possible postpone the final decision related to rejected modules for an expert analysis or even for another classifier using extra domain knowledge.MethodWe develop a SDP method called rejoELM and its variant, IrejoELM. Both methods were built upon the weighted extreme learning machine (ELM) with reject option that makes it possible postpone the final decision of non-classified modules, the rejected ones, to another moment. While rejoELM aims to maximize the accuracy for a rejection rate, IrejoELM maximizes the F-measure. Hence, IrejoELM becomes an alternative for classification with reject option for imbalanced datasets.ResultsrejoEM and IrejoELM are tested on five datasets of source code metrics extracted from real world open-source software projects. Results indicate that rejoELM has an accuracy for several rejection rates that is comparable to some state-of-the-art classifiers with reject option. Although IrejoELM shows lower accuracies for several rejection rates, it clearly outperforms all other methods when the F-measure is used as a performance metric.ConclusionIt is concluded that rejoELM is a valid alternative for classification with reject option problems when classes are nearly equally represented. On the other hand, IrejoELM is shown to be the best alternative for classification with reject option on imbalanced datasets. Since SDP problems are usually characterized as imbalanced learning problems, the use of IrejoELM is recommended.     

Designing educational software as a re-usable resource

Abstract The production of educational software is moving from a focus on courseware produced by the individual lecturer to the development of educational resources that can be shared and accessed from a wide variety of teaching sites. This change has a number of implications. Firstly, different resources must be capable of being seamlessly integrated into a specific teaching package. Secondly, collaboration between institutions will be increasingly important to ensure that resources so produced are sufficiently generic to be of interest to those outside the development team. Thirdly, management procedures to direct and control this collaborative effort are required. This paper details how the distributed hypermedia environment provided by the World Wide Web may be effectively exploited to realise these three goals.     

Semantic metrics for software products

Like all engineering disciplines, software engineering relies on quantitative analysis to support rationalized decision making. Software engineering researchers and practitioners have traditionally relied on software metrics to quantify attributes of software products and processes. Whereas traditional software metrics are typically based on a syntactic analysis of software products, we introduce and discuss metrics that are based on a semantic analysis: our metrics do not reflect the form or structure of software products, but rather the properties of their function. At a time when software systems grow increasingly large and complex, the focus on diagnosing, identifying and removing every fault in the software product ought to relinquish the stage to a more measured, more balanced, and more realistic approach, which emphasizes failure avoidance, in addition to fault avoidance and fault removal. Semantic metrics are a good fit for this purpose, reflecting as they do a system’s ability to avoid failure rather than its proneness to being free of faults.     

Designing for recovery [software design]

How should you design your software to detect, react, and recover from exceptional conditions? If you follow Jim Shore's advice and design with a fail fast attitude, you won't expend any effort recovering from failures. Shore argues that a "patch up and proceed" strategy often obfuscates problems. Shore's simple design solution is to write code that checks for expected values upon entry and returns failure notifications when it can't fulfil its responsibilities. He argues that careful use of assertions allows for early and visible failure, so you can quickly identify and correct problems.     

Evaluation of Workflow-type software products: a case study

The main objective of this paper is to propose a set of indicators for the evaluation of Workflow software-type products within the context of Information Systems. This paper is mainly based on a comprehensive bibliographical review of all topics referring to the Workflow Technology and Information Systems. Next, sets of indicators are presented for the selection of a Workflow software based on the realities of the business world, including a method of examination so as to obtain an integral evaluation on the Workflow software. Finally, the evaluation method for two types of Workflow software is applied: Lotus Domino/Notes^® and Microsoft Exchange^®, for the billing subsystems of a company called MANAPRO Consultants, Inc.^®.     

Motivated humans for reliable software products

This paper focuses on the software engineer, as opposed to some software engineering discipline. The author's worldwide experience in software development has resulted in concluding that the vast majority of problems encountered while developing software are more people oriented rather than technology based. Therefore, for there to be any improvements in the reliability of software, it may be wise to revisit some of the people issues, otherwise, even the best methods, tools and techniques will not make an impact on the software development process so as to result in higher levels of software quality. Many are the problems which the software engineer is faced with while trying to piece together the complex information systems that the current global market dictates. Lack of office space and engineer concentration, unpaid overtime, non-productive meeting cultures, performance appraisals and absence of team work all contribute to the demotivation of the software engineer. Trying to introduce a new tool or a new technique to a demotivated staff is simply a waste of time. Thus, it is of paramount importance to realize that in the labour intensive software development world, the focus must first be on the human factor. Basic human nature has not changed over the years, therefore, the author sought out solutions from the past regarding the management of people, so as to be applied today in the development of software. This paper concludes with a ‘euphoria quadrant’ so as to provide a simple means for software producing units to gauge their management style and their overall working environment.     

Designing a new software tool for Digital Imagery based on P systems

In this paper we present a new software tool for dealing with the problem of segmentation in Digital Imagery. The implementation is inspired in the design of a tissue-like P system which solves the problem in constant time due the intrinsic parallelism of Membrane Computing devices.     

Designing an assembly line for modular products

To respond to the challenge of agile manufacturing, companies are striving to provide a large variety of products at low cost. Product modularity has become an important issue. It allows to produce different products through combination of standard components. One of the characteristics of modular products is that they share the same assembly structure for many assembly operations. The special structure of modular products provides challenges and opportunities for operational design of assembly lines. In this paper, an approach for design of assembly lines for modular products is proposed. This approach divides the assembly line into two subassembly lines: a subassembly line for basic assembly operations and a subassembly line for variant assembly operations. The design of the subassembly line for basic operations can be viewed as a single product assembly line balancing problem and be solved by existing line balancing methods. The subassembly line for the variant operations is designed as a two-station flowshop line and is balanced by a two-machine flowshop scheduling method. A three-station flowshop line for a special structure of modular products is proposed and illustrated with an example.     

Is your software ready for release?

The author presents a method derived from the exponential model of reliability to answer the question of whether software is good enough for release. This zero-failure method is a decision technique that specifies the number of test hours before software release in which no additional test failures are permitted to be found. This method has been applied at the release of 75 software products. The initial results indicate that the method does provide useful information for quality-assurance purposes     

The menu metaphor: food for thought

Menu selection in human/computer interaction is a metaphor of the restaurant menu. Although menu selection is widely used, its scope is currently limited, ill-defined, and information lean. A comparison of the restaurant menu and the computer menu reveal three avenues of improvement in menu systems. The correspondence of elements and features between restaurant and computer menus suggests that this powerful metaphor should be more fully developed. Second, there are a number of advantages of dynamic computer menus over static listings common to restaurants. Finally, restaurant menus currently have the advantage of breadth, richness, and graphic layout as well as a natural support system (the server) that is unparalleled in current computer applications. An analysis of deficiences in computer menus should prove invaluable in developing the next generation of menu selection techniques.     

Designing low-complexity electrical consumer products for ecological use

This study examined the environmental impact of low-complexity electrical consumer products during their use in a domestic context. In the experimental scenario, 48 users were asked to use a kettle under different conditions. On-product information (OPI), task instruction, and kettle design were employed as independent variables in a mixed multi-factorial design to examine their effects on different parameters of ecological performance (e.g., water and electricity consumption). Measures of user variables (environmental concern, knowledge, domestic habits, environmental control beliefs) were also taken to examine their relationship with performance parameters. The results revealed main effects of ecological task instruction, OPI and (partly) kettle design on ecological user behaviour. Habits, environmental concern and control beliefs were found to be related to performance parameters whereas knowledge was not. The implications of the results for product design are discussed against the background of a strong prevalence of habits and low ecological user motivation.     

A formal process for evaluating COTS software products

A software product evaluation process grounded in mathematics and decision theory can effectively determine product quality and suitability with less risk and at lower cost than conventional methods     

Observations on meeting usability goals for software products

Making software products more usable has been stated as an industrial, national, and even international goal. Constructive exchanges between those working in universities to build theory and those working in industry to build products have been identified as one way to speed the achievement of this goal. Programmes within IBM have encouraged such exchanges. Drawing on my experience in IBM, I outline some of the problems in setting and meeting software usability goals, discuss briefly the nature of collaborative work, and suggest ways to facilitate working together for mutual benefit despite possible differences in culture and purpose.     

Comparisons of optimal release policies for software systems

In a software product management, it is an important problem to determine the optimal release timing which minimizes the total expected cost incurred in both testing and operation phases. In this paper, we compare the performance between two kinds of software release methods, which are referred to as the T-policy and the N-policy. Based on the existing software reliability growth models, we formulate the expected cost functions and derive analytically the optimal policies under these control methods. Also, we derive a criterion for which control methods should be adopted. Finally, in numerical examples, we calculate the optimal release policies for several cost parameters.     

Designing a two-rank acceptance sampling plan for quality inspection of geospatial data products

To address the disadvantages of classical sampling plans designed for traditional industrial products, we originally propose a two-rank acceptance sampling plan (TRASP) for the inspection of geospatial data outputs based on the acceptance quality level (AQL). The first rank sampling plan is to inspect the lot consisting of map sheets, and the second is to inspect the lot consisting of features in an individual map sheet. The TRASP design is formulated as an optimization problem with respect to sample size and acceptance number, which covers two lot size cases. The first case is for a small lot size with nonconformities being modeled by a hypergeometric distribution function, and the second is for a larger lot size with nonconformities being modeled by a Poisson distribution function. The proposed TRASP is illustrated through two empirical case studies. Our analysis demonstrates that: (1) the proposed TRASP provides a general approach for quality inspection of geospatial data outputs consisting of non-uniform items and (2) the proposed acceptance sampling plan based on TRASP performs better than other classical sampling plans. It overcomes the drawbacks of percent sampling, i.e., “strictness for large lot size, toleration for small lot size,” and those of a national standard used specifically for industrial outputs, i.e., “lots with different sizes corresponding to the same sampling plan.”