Exploring the eradication of code smells: An empirical and theoretical perspective

This article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2010 Hindawi Publishing CorporationCode smells reflect code decay, and, as such, developers should seek to eradicate such smells through application of “deodorant” in the form of one or more refactorings. However, a relative lack of studies exploring code smells either theoretically or empirically when compared with literature on refactoring suggests that there are reasons why smell eradication is neither being applied in anger, nor the subject of significant research. In this paper, we present three studies as supporting evidence for this stance. The first is an analysis of a set of five, open-source Java systems in which we show very little tendency for smells to be eradicated by developers; the second is an empirical study of a subsystem of a proprietary, C# web-based application where practical problems arise in smell identification and the third, a theoretical enumeration of smell-related refactorings to suggest why smells may be left alone from an effort perspective. Key findings of the study were that first, smells requiring application of simple refactorings were eradicated in favour of smells requiring more complex refactorings; second, a wide range of conflicts and anomalies soon emerged when trying to identify smelly code; an interesting result with respect to comment lines was also observed. Finally, perceived (estimated) effort to eradicate a smell may be a key factor in explaining why smell eradication is avoided by developers. The study thus highlights the need for a clearer research strategy on the issue of code smells and all aspects of their identification and measurement.The research in this paper was supported by a grant from the UK Engineering and Physical Sciences Research Council (EPSRC) (Grant no: EP/G031126/1

Phenotypic heterogeneity and genetic modification of P102L inherited prion disease in an international series

The largest kindred with inherited prion disease P102L, historically Gerstmann-Sträussler-Scheinker syndrome, originates from central England, with émigrés now resident in various parts of the English-speaking world. We have collected data from 84 patients in the large UK kindred and numerous small unrelated pedigrees to investigate phenotypic heterogeneity and modifying factors. This collection represents by far the largest series of P102L patients so far reported. Microsatellite and genealogical analyses of eight separate European kindreds support multiple distinct mutational events at a cytosine-phosphate diester-guanidine dinucleotide mutation hot spot. All of the smaller P102L kindreds were linked to polymorphic human prion protein gene codon 129M and were not connected by genealogy or microsatellite haplotype background to the large kindred or each other. While many present with classical Gerstmann-Sträussler-Scheinker syndrome, a slowly progressive cerebellar ataxia with later onset cognitive impairment, there is remarkable heterogeneity. A subset of patients present with prominent cognitive and psychiatric features and some have met diagnostic criteria for sporadic Creutzfeldt-Jakob disease. We show that polymorphic human prion protein gene codon 129 modifies age at onset: the earliest eight clinical onsets were all MM homozygotes and overall age at onset was 7 years earlier for MM compared with MV heterozygotes (P = 0.02). Unexpectedly, apolipoprotein E4 carriers have a delayed age of onset by 10 years (P = 0.02). We found a preponderance of female patients compared with males (54 females versus 30 males, P = 0.01), which probably relates to ascertainment bias. However, these modifiers had no impact on a semi-quantitative pathological phenotype in 10 autopsied patients. These data allow an appreciation of the range of clinical phenotype, modern imaging and molecular investigation and should inform genetic counselling of at-risk individuals, with the identification of two genetic modifiers

An empirical investigation of issues relating to software immigrants

This thesis focuses on the issue of people in software maintenance and, in particular, on software immigrants – developers who are joining maintenance teams to work with large unfamiliar software systems. By means of a structured literature review this thesis identifies a lack of empirical literature in Software Maintenance in general and an even more distinct lack of papers examining the role of People in Software Maintenance. Whilst there is existing work examining what maintenance programmers do the vast majority of it is from a managerial perspective, looking at the goals of maintenance programers rather than their day-to-day activities. To help remedy this gap in the research a series of interviews with maintenance programmers were undertaken across a variety of different companies. Four key results were identified: maintainers specialise; companies do not provide adequate system training; external sources of information about the system are not guaranteed to be available; even when they are available they are not considered trustworthy. These results combine together to form a very challenging picture for software immigrants. Software immigrants are maintainers who are new to working with a system, although they are not normally new to programming. Although there is literature on software immigrants and the activities they undertake, there is no comparative literature. That is, literature that examines and compares different ways for software immigrants to learn about the system they have to maintain. Furthermore, a common feature of software immigrants learning patterns is the existence and use of mentors to impart system knowledge. However, as the interviews show, often mentors are not available which makes examining alternative ways of building a software immigrants level-of-understanding about the system they must maintain all the more important. As a result the final piece of work in this thesis is the design, running and results of a controlled laboratory experiment comparing different, work based, approaches to developing a level-of-understanding about a system. Two approaches were compared, one where subjects actively worked and altered the code while a second group took a passive ‘hands-off’ approach. The end result showed no difference in the level-of-understanding gained between the subjects who performed the active task and those that performed the passive task. This means that there is no benefit to taking a hands-off approach to building a level-of-understanding about new code in the hostile environment identified from the literature and interviews and software immigrants should start working with the code, fulfilling maintenance requests as soon as possible

Why Modern Open Source Projects Fail

Open source is experiencing a renaissance period, due to the appearance of modern platforms and workflows for developing and maintaining public code. As a result, developers are creating open source software at speeds never seen before. Consequently, these projects are also facing unprecedented mortality rates. To better understand the reasons for the failure of modern open source projects, this paper describes the results of a survey with the maintainers of 104 popular GitHub systems that have been deprecated. We provide a set of nine reasons for the failure of these open source projects. We also show that some maintenance practices -- specifically the adoption of contributing guidelines and continuous integration -- have an important association with a project failure or success. Finally, we discuss and reveal the principal strategies developers have tried to overcome the failure of the studied projects.Comment: Paper accepted at 25th International Symposium on the Foundations of Software Engineering (FSE), pages 1-11, 201

Evaluating EGM2008 over East Antarctica

The release of EGM2008 and associated products such as grids of mean dynamic ocean topography offer the possibility of utilising the extensive historical record in Antarcticawith today's modern satellite sensing techniques. In this study, we use data acquired at the Mawson, Davis, Casey and Scott and McMurdo stations in East Antarctica to investigate the performance of EGM2008 over this region. EGM2008 over Antarctica is entirely dependent on the EGM2008-adopted global GRACE satellite-derived gravity field. This is in contrast to most other regions of the Earth, where there are also contributions from terrestrial gravity and/or altimeter satellites. We determine, over East Antarctica, and at our four test sites that EGM2008 should be used with caution when precisions better than one metre are required. The precisions at the test sites are better than this, but the evidence is that the four test sites are probably not representative of the large area of East Antarctica they are being forced to represent. Notwithstanding any of the above, EGM2008 represents a significant step forward in East Antarctica and that the use of test stations and regions where there is little or no complementary data is a valid method of investigating the performance of the model

Increasing Epistemic Value And Rate Through Flow Value Co-Creation Perspective Of Service-Dominant Logic Theory

Background – Flow value co-creation is a psychological condition where a person feels pleasure in using a product or service. This concept starts with Service-Dominant Logic Theory (SDL) which indicates that SDL tends in the domain of marketing services. Aim –This study aims to identify the mediation of Flow value co-creation (FVC) with Epistemic (EPV) and Rate (RT) variables. Design / methodology / approach – This study describes the unaffected relationship between Epistemic values and Ratings mediated by the new concept of Flow value co-creation. The PLS-SEM equation engineering model uses the retrieval technique. This study involved a total of 286 Y generations of Shopee application users Y. Findings – The results showed that Flow value co-creation increased Rate. Shopee application users especially the Y generation feel shared comfort. Conclusion - The FVC relationship to RT has a logical impact in which the more comfortable, enjoyable, and safe using an application, the better the RT. The model can be assumed that Flow value co-creation can mediate the inconsistency of complex debates from previous studies regarding Epistemic Correlation (EPV) at Rate (RT). Research implication – For startup makers in the form of applications to survive. First, updates for consumer users affect user enjoyment. Second, the evaluation of applications for target markets such as MSMEs and consumers in their use will have an impact on the market. Third, Flow value co-creation affects the stakeholders in improving application performance. Limitations – The number of respondents is only in the Bantul area and is under 300 respondents, the development of variables such as the length of time the user is used, the frequency of applications used through advertisements

A comparative investigation of consumers’ attitudes toward marketing practices of hypermarket retailers in Thailand

Purpose The purpose of this paper is to contribute to the understanding of hypermarket retailers' marketing efforts by exploring consumers' attitudes toward marketing practices (CATMPs) of three retailers (Tesco-Lotus, Big C, and Carrefour) in Thailand.Design/methodology/approach A non-probability convenience sampling procedure was employed. The data were collected from an intercept survey administered face to face. Three versions were tailored to each specific hypermarket retailer using similar questions related to consumers' attitudes toward different areas of marketing practices. The measures were adapted from the Index of Consumer Sentiment toward marketing and consumers' attitudes toward marketing.Findings The results showed that although Thai consumers displayed different attitudes toward retail services, positive advertising, and fair price, they expressed similar attitudes toward business provisions and product quality across samples. Main and interaction effects of a limited number of demographic variables were also identified.Research limitations/implications Multinational hypermarket retailers need to understand the similarities and differences related to areas of their marketing practices to be able to market effectively to Thai consumers. However, since the data were obtained from one city, the major limitation in the study is the generalizability of the findings.Originality/value This study is among the first to attempt to investigate CATMPs of multinational hypermarket retailers operating in Thailand