Is the Stack Distance Between Test Case and Method Correlated With Test Effectiveness?

Mutation testing is a means to assess the effectiveness of a test suite and its outcome is considered more meaningful than code coverage metrics. However, despite several optimizations, mutation testing requires a significant computational effort and has not been widely adopted in industry. Therefore, we study in this paper whether test effectiveness can be approximated using a more light-weight approach. We hypothesize that a test case is more likely to detect faults in methods that are close to the test case on the call stack than in methods that the test case accesses indirectly through many other methods. Based on this hypothesis, we propose the minimal stack distance between test case and method as a new test measure, which expresses how close any test case comes to a given method, and study its correlation with test effectiveness. We conducted an empirical study with 21 open-source projects, which comprise in total 1.8 million LOC, and show that a correlation exists between stack distance and test effectiveness. The correlation reaches a strength up to 0.58. We further show that a classifier using the minimal stack distance along with additional easily computable measures can predict the mutation testing result of a method with 92.9% precision and 93.4% recall. Hence, such a classifier can be taken into consideration as a light-weight alternative to mutation testing or as a preceding, less costly step to that.Comment: EASE 201

Evaluating the Impact of Critical Factors in Agile Continuous Delivery Process: A System Dynamics Approach

Continuous Delivery is aimed at the frequent delivery of good quality software in a speedy, reliable and efficient fashion – with strong emphasis on automation and team collaboration. However, even with this new paradigm, repeatability of project outcome is still not guaranteed: project performance varies due to the various interacting and inter-related factors in the Continuous Delivery 'system'. This paper presents results from the investigation of various factors, in particular agile practices, on the quality of the developed software in the Continuous Delivery process. Results show that customer involvement and the cognitive ability of the QA have the most significant individual effects on the quality of software in continuous delivery

A research review of quality assessment for software

Measures were recommended to assess the quality of software submitted to the AdaNet program. The quality factors that are important to software reuse are explored and methods of evaluating those factors are discussed. Quality factors important to software reuse are: correctness, reliability, verifiability, understandability, modifiability, and certifiability. Certifiability is included because the documentation of many factors about a software component such as its efficiency, portability, and development history, constitute a class for factors important to some users, not important at all to other, and impossible for AdaNet to distinguish between a priori. The quality factors may be assessed in different ways. There are a few quantitative measures which have been shown to indicate software quality. However, it is believed that there exists many factors that indicate quality and have not been empirically validated due to their subjective nature. These subjective factors are characterized by the way in which they support the software engineering principles of abstraction, information hiding, modularity, localization, confirmability, uniformity, and completeness

The Quest for a Practical Sophomore-Level Software Engineering Course

This paper describes our efforts starting since 2014 when we began developing a practical introductory sophomore-level software engineering course. The aim is to guide students into the fundamental theory and practice of building reliable software, with an emphasis on agile and object-oriented practices. Course topics revolve around three main themes: 1) managing complexity (how to model and scale software), 2) achieving quality (how to minimize defects) and 3) supporting usability (how to deliver user functionality). Students are exposed to theoretical and practical aspects of software production, such as software life-cycle models, strong-typing, testing, documentation, graphical user interfaces, UML, design patterns, version control systems and software deployment. The course is in constant evolution: near-future plans include adding build automation tools and DevOps concepts. We made the early decision to use reference materials available to our students at no cost; therefore, all reference materials are accessed online through resources afforded by our library

The small business assistance dilemma: is the disparity between the offerings of support agencies and the needs of business irreconcilable?

There is a wide range of service providers who have varying motives for supplying assistance to small businesses in Australia. Despite the sizeable numbers of both suppliers and consumers of assistance it is believed that the marketplace for small business assistance operates inefficiently. This inefficiency is described as a disparity or misfit between the learning opportunities offered by service providers to small business and the learning needs of small business owner / operators. This paper provides an analysis of the learning activity that currently exists in the small enterprise sector. The role of communication in bringing supply and demand closer together is discussed and a proposition is developed to alleviate the learning disparity via a more proactive approach to communication by service providers. Two small enterprise projects are used to test the proposition. The findings provide guidance for the more effective functioning of organisations that serve and support small businesses

A Load of Cobbler’s Children: Beyond the Model Designing Processor

HCI has developed rich understandings of people at work and at play with technology: most people that is, except designers, who remain locked in the information processing paradigm of first wave HCI. Design methods are validated as if they were computer programs, expected to produce the same results on a range of architectures and hardware. Unfortunately, designers are people, and thus interfere substantially (generally to good effects) with the ‘code’ of design methods. We need to rethink the evaluation and design of design and evaluation methods in HCI. A logocentric proposal based on resource function vocabularies is presented

Why It Worked: Critical Success Factors of a Financial Reform Project in Africa

Little is written about the critical success factors that make or break a project implementing a public financial management reform in Africa. Based on the twelve year experience of Harvard's DSA project which transformed Ethiopia's financial management in the third best on the continent, this paper presents the key factors of the projects success: task, context, patrons, roles, staff and decisions. The task was focused from the start on the basics of financial control (budget and accounts and their budget classification, chart of accounts and financial calendar) and the development of an often forgotten end state in PFM reform--the self-accounting unit. Three features of context supported the project: political (close ties between the US and Ethiopia government established during the civil war), task environment (a hard budget constraint) and, serendipity (a war that ensure one set of cooks in the kitchen and removed the inevitable critique by foreign aid agencies, and the government policy of second stage devolution--which made the focal point of district level decentralization). The third CSF, the projects patrons, stayed the course, met stated commitments and did not meddle. The project performed four roles (go-between in the vacuum of decentralization), decider (making the key decisions on pilots), first responder (providing PFM innovations not specified in the terms of reference) and perhaps most important, the furniture (an object that could be kicked and blamed). The project was able to assemble the array of essential staff: all rounders, managers, technicians, networkers and a closer.

Tax Decentralisation and local Government size

The aim of this paper is to re-examine the relationship between fiscal federalism and the size of local governments. Traditionally, the empirical studies have focused on the different accountability power of grants and local taxes, concluding that the former encourages the growth and the latter contributes to contain local public spending. Yet, the existing literature is more silent about the possibility that different types of tax autonomy may still have differential impacts on the expansion of the local public sector. The paper addresses this issue by introducing a new testable hypothesis - the “Tax Separation Hypothesis” (TSH) - according to which tax decentralisation organised on tax bases used only by local governments would favour most the containment of local public expenditures, while that organised on tax base sharing (i.e. piggybacking mechanisms) is not expected to have a significant impact on the local government size. Using an unbalanced panel data set of OECD countries, we adopt the novel approach of disentangling the impact of local taxes - on income, property, and goods and services - on the size of the local public sector. In particular, property taxes only - mostly based on a “tax separation” scheme - seem to have a negative impact on the size of local government. Instead, both income taxes and general taxes on goods and services – often shared with central governments – have uncertain impacts on the size of local governments (and more frequently positive). We conclude that tax decentralisation is a necessary condition to contain local public expenditures, yet it is not sufficient, as a tax separation scheme would in fact be required.Fiscal decentralisation; Tax sharing; Tax separation; Property taxes; Local government size.