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Software engineering is a socio-technical endeavor, and while many of our contributions focus on technical aspects, human stakeholders such as software developers are directly affected by and can benefit from our research and tool innovations. In this paper, we question how much of our research addresses human and social issues, and explore how much we study human and social aspects in our research designs. To answer these questions, we developed a socio-technical research framework to capture the main beneficiary of a research study (the who), the main type of research contribution produced (the what), and the research strategies used in the study (how we methodologically approach delivering relevant results given the who and what of our studies). We used this Who-What-How framework to analyze 151 papers from two well-cited publishing venues—the main technical track at the International Conference on Software Engineering, and the Empirical Software Engineering Journal by Springer—to assess how much this published research explicitly considers human aspects. We find that although a majority of these papers claim the contained research should benefit human stakeholders, most focus predominantly on technical contributions. Although our analysis is scoped to two venues, our results suggest a need for more diversification and triangulation of research strategies. In particular, there is a need for strategies that aim at a deeper understanding of human and social aspects of software development practice to balance the design and evaluation of technical innovations. We recommend that the framework should be used in the design of future studies in order to steer software engineering research towards explicitly including human and social concerns in their designs, and to improve the relevance of our research for human stakeholders. [ABSTRACT FROM AUTHOR]

It has been argued that reporting software engineering experiments in a standardized way helps researchers find relevant information, understand how experiments were conducted and assess the validity of their results. Various guidelines have been proposed specifically for software engineering experiments. The benefits of such guidelines have often been emphasized, but the actual uptake and practice of reporting have not yet been investigated since the introduction of many of the more recent guidelines. In this research, we utilize a mixed-method study design including sequence analysis techniques for evaluating to which extent papers follow such guidelines. Our study focuses on the four most prominent software engineering journals and the time period from 2000 to 2020. Our results show that many experimental papers miss information suggested by guidelines, that no de facto standard sequence for reporting exists, and that many papers do not cite any guidelines. We discuss these findings and implications for the discipline of experimental software engineering focusing on the review process and the potential to refine and extend guidelines, among others, to account for theory explicitly. [ABSTRACT FROM AUTHOR]

This document is a guest editorial for a special issue of the journal "Programming & Computer Software" titled "Recent Trends on Advanced Computing: The Converging Technologies." The issue features research and practical implementation results from researchers and industry experts in computer science, engineering, and technology. The papers cover a range of topics including microservices, software quality, user engagement on social media, non-functional requirements, medical software architecture, fallacies in political speeches, intelligent learning environments, and more. The guest editors for this special issue are Prof. Dr. Andrei Tchernykh, Prof. Reyes Juárez Ramírez, Dr. Esteban Mocskos, and Prof. Sergio Nesmachnow. [Extracted from the article]

Software engineering (SE) research should be relevant to industrial practice. There have been regular discussions in the SE community on this issue since the 1980's, led by pioneers such as Robert Glass. As we recently passed the milestone of "50 years of software engineering", some recent positive efforts have been made in this direction, e.g., establishing "industrial" tracks in several SE conferences. However, many researchers and practitioners believe that we, as a community, are still struggling with research relevance and utility. The goal of this paper is to synthesize the evidence and experience-based opinions shared on this topic so far in the SE community, and to encourage the community to further reflect and act on the research relevance. For this purpose, we have conducted a Multi-vocal Literature Review (MLR) of 54 systematically-selected sources (papers and non peer-reviewed articles). Instead of relying on and considering the individual opinions on research relevance, mentioned in each of the sources, the MLR aims to synthesize and provide the "holistic" view on the topic. The highlights of our MLR findings are as follows. The top three root causes of low relevance, discussed in the community, are: (1) Researchers having simplistic views (or wrong assumptions) about SE in practice; (2) Lack of connection with industry; and (3) Wrong identification of research problems. The top three suggestions for improving research relevance are: (1) Using appropriate research approaches such as action-research; (2) Choosing relevant (practical) research problems; and (3) Collaborating with industry. By synthesizing all the discussions on this important topic so far, this paper aims to encourage further discussions and actions in the community to increase our collective efforts to improve the research relevance. Furthermore, we raise the need for empirically-grounded and rigorous studies on the relevance problem in SE research, as carried out in other fields such as management science. [ABSTRACT FROM AUTHOR]

The systematic review (SR) is a methodology used to find and aggregate all relevant existing evidence about a specific research question of interest. One of the activities associated with the SR process is the selection of primary studies, which is a time consuming manual task. The quality of primary study selection impacts the overall quality of SR. The goal of this paper is to propose a strategy named 'Score Citation Automatic Selection' (SCAS), to automate part of the primary study selection activity. The SCAS strategy combines two different features, content and citation relationships between the studies, to make the selection activity as automated as possible. Aiming to evaluate the feasibility of our strategy, we conducted an exploratory case study to compare the accuracy of selecting primary studies manually and using the SCAS strategy. The case study shows that for three SRs published in the literature and previously conducted in a manual implementation, the average effort reduction was 58.2 % when applying the SCAS strategy to automate part of the initial selection of primary studies, and the percentage error was 12.98 %. Our case study provided confidence in our strategy, and suggested that it can reduce the effort required to select the primary studies without adversely affecting the overall results of SR. [ABSTRACT FROM AUTHOR]

In this full review paper, the recent emerging trends in Computing Structures, Software Science, and System Applications have been reviewed and explored to address the recent topics and contributions in the era of the Software and Computing fields. This includes a set of rigorously reviewed world-class manuscripts addressing and detailing state-of-the-art, framework, implemented approaches and techniques research projects in the areas of Software Technology & Automation, Networking, Systems, Computing Sciences and Software Engineering, Big Data and E-learning. Based on this systematic review, we have put some recommendations and suggestions for researchers, practitioners and scholars to improve their research quality in this area. [ABSTRACT FROM AUTHOR]

Requirements engineering (RE) has attracted a great deal of attention from researchers and practitioners in recent years. Requirements engineering education (REE) is therefore an important undertaking if the field is to have professionals who are capable of successfully accomplishing software projects. This increasing interest demands that academia should provide software engineering students with a solid foundation in the subject matter. This paper aims to identify and to present the current research on REE that is available at present, and to select useful approaches and needs for future research. A systematic mapping study was therefore performed to classify the selected studies into five classification criteria: research type, empirical type, contribution type, RE activity, and curricula. A total of 79 papers were selected and classified according to these criteria. The results of this systematic mapping study are discussed, and a list of advice obtained from the REE literature for instructors is provided. [ABSTRACT FROM AUTHOR]

User participation and involvement in software development are considered to be essential for a successful software system. Three research areas, human aspects of software engineering, requirements engineering, and information systems, study these topics from various perspectives. We think it is important to analyze user participation and involvement in software engineering comprehensively to encourage further research in this area. We investigate the evidence on effects of user participation and involvement on system success and we explore which methods are available in literature. A systematic mapping study was conducted. The systematic search yielded 3,698 hits, from which we identified 289 unique papers. These papers were reviewed by the first author based on inclusion and exclusion criteria. The second author validated the selection of papers by reviewing the reasons for exclusion and inclusion and the corresponding papers on a sample base. 58 of the 289 papers were selected (22 statistical survey and meta-study papers and 36 methods papers). Based on the empirical evidence of the surveys and meta-studies, we developed a meta-analysis of structural equation models. This overview demonstrates that most papers showed positive correlations between aspects of development processes (including user participation) and human aspects (including user involvement) and system success. The analysis of the proposed solutions from the method papers revealed a wide variety of user participation and involvement practices for most activities within software development. [ABSTRACT FROM AUTHOR]

Automated software transformations and the process of automated program repair and improvement are an important aspect of modern software engineering practices. In this paper, we describe a system which uses a graph-based deep learning model that can be trained to automatically transform and improve computer programs. By operating on language-agnostic, universal graph-like structures easily extractable from source code files (abstract syntax trees), the deep learning agent learns which transformations should be effectively applied to various structures recognized in the source code in order to improve it. By defining a metric which we want to improve and introducing an optimization task—a reinforcement learning setting, an agent learns to automatically apply a chain of transformations to the program, drastically improving it. While similar program improvement processes exist, they exclusively use exhaustive search algorithms to try all the possible code transformations which is a long process susceptible to local optimum issues. Our solution aims to model and embed structural knowledge about the programs being transformed which greatly helps the agent to choose best possible code transformations to apply. Elements of the approach we present in this paper are further applicable not just to automatic software improvement tasks, but also to other code-related tasks. [ABSTRACT FROM AUTHOR]

Models are the key tools humans use to manage complexity in description, development, and analysis. This applies to all scientific and engineering disciplines and in particular to the development of software and data-intensive systems. However, different methods and terminologies have become established in the individual disciplines, even in the sub-fields of Informatics, which raises the need for a comprehensive and cross-sectional analysis of the past, present, and future of modeling research. This paper aims to shed some light on how different modeling disciplines emerged and what characterizes them with a discussion of the potential toward a common modeling future. It focuses on the areas of software, data, and process modeling and reports on an analysis of the research approaches, goals, and visions pursued in each, as well as the methods used. This analysis is based on the results of a survey conducted in the communities concerned, on a bibliometric study, and on interviews with a prominent representative of each of these communities. The paper discusses the different viewpoints of the communities, their commonalities and differences, and identifies possible starting points for further collaboration. It further discusses current challenges for the communities in general and modeling as a research topic in particular and highlights visions for the future. [ABSTRACT FROM AUTHOR]

An inherent problem in software engineering is that competing prediction systems have been found to produce conflicting results. Yet accurate prediction is crucial because the complexity and quality of software requirements have dramatically changed in recent years, and consumers have become considerably more demanding in terms of the cost, timeframe, and quality of software solutions. Moreover, these variables may also be in direct conflict and can only be resolved by the optimum development of software by using reliable software engineering strategies. In this paper, a novel method based on the integration of the mine blast algorithm (MBA) and the simulated annealing (SA) algorithm is used to create input connection weights and biases for a back propagation neural network (BPNN) for the purpose of addressing the software fault prediction problem (SFP). The aim of hybridizing the MBA and SA is to find a way to efficiently explore and manipulate the search space. The proposed MBA-SA was tested on 18 datasets for SFP. The results indicated that the MBA-SA outperformed the MBA on all datasets. These results were subjected to additional statistical validity, boxplot distribution, and convergence analysis. Furthermore, a comparative evaluation of MBA-SA against twenty state-of-the-art methods for various output metrics was performed, and the result indicated that the hybrid MBA-SA outperformed most other state-of-the-art methods in the majority of datasets. [ABSTRACT FROM AUTHOR]

The text of software knowledge community contains abundant knowledge of software engineering field. The software knowledge entity and relation can be extracted automatically and efficiently to form the software knowledge graph, which is helpful for software knowledge-centric intelligent applications, such as intelligent question answering, automatic document generation and software expert recommendation. Most existing methods are confronted with problems of task dependence and entity overlap. In this paper, we propose a software knowledge extraction method based on span-level contrastive learning. From the level of sentence sequence modelling, we model the sentence sequence with span as a unit, and generate abundant positive and negative samples of entity span through the span representation layer to avoid the problem that the token-level method cannot select overlapping entities. From the level of feature learning, we propose supervised entity contrastive learning and relation contrastive learning, which obtain enhanced feature representation of entity span and entity pair through positive and negative sample enhancement and contrastive loss function construction. Experiments are conducted on the dataset which is constructed based on texts of the StackOverflow, and show that our approach achieves a better performance than baseline models. [ABSTRACT FROM AUTHOR]

Research studies in software maintenance are notoriously hard to reproduce due to lack of datasets, tools, implementation details (e.g., parameter values, environmental settings) and other factors. The progress in the field is hindered by the challenge of comparing new techniques against existing ones, as researchers have to devote a large portion of their resources to the tedious and error-prone process of reproducing previously introduced approaches. In this paper, we address the problem of experiment reproducibility in software maintenance and provide a long-term solution towards ensuring that future experiments will be reproducible and extensible. We conducted a preliminary mapping study of a number of representative maintenance techniques and approaches and implemented them as a set of experiments and a library of components that we make publicly available with TraceLab, called the Component Library. The goal of these experiments and components is to create a body of actionable knowledge that would (i) facilitate future research and (ii) allow the research community to contribute to it as well. In addition, to illustrate the process of using and adapting these techniques, we present an example of creating new techniques based on existing ones, in order to produce improved results. [ABSTRACT FROM AUTHOR]

Testing safety-critical systems is crucial since a failure or malfunction may result in death or serious injuries to people, equipment, or environment. An important challenge in testing is the derivation of test cases that can identify the potential faults. Model-based testing adopts models of a system under test and/or its environment to derive test artifacts. This paper aims to provide a systematic mapping study to identify, analyze, and describe the state-of-the-art advances in model-based testing for software safety. The systematic mapping study is conducted as a multi-phase study selection process using the published literature in major software engineering journals and conference proceedings. We reviewed 751 papers and 36 of them have been selected as primary studies to answer our research questions. Based on the analysis of the data extraction process, we discuss the primary trends and approaches and present the identified obstacles. This study shows that model-based testing can provide important benefits for software safety testing. Several solution directions have been identified, but further research is critical for reliable model-based testing approach for safety. [ABSTRACT FROM AUTHOR]

Requirements prioritization is essential for development of quality software products. Requirements prioritization helps focus on the most important requirements between the available software requirements. This process is also called preserving core vision according to customer viewpoint or managing the quality requirements. Many requirements prioritization techniques have been proposed in the Software Engineering field. However, one requirement prioritization technique can only be generalized for some software projects. This research effort aims to develop a sustainable hybrid model for requirements prioritization, utilizing critical software project factors. The prioritization technique is shortlisted from a pool of software prioritization techniques, based on these project factors and their quantized scores. The proposed model is equipped with state-of-the-art literature to provide a customized prioritization technique improving the requirements prioritization process for a specific software project. The paper also presents popular software prioritization techniques used in the software industry and an extensive comparison using a thorough empirical analysis. Finally, the quantization of the software project factors for each technique has been assessed for better understanding, and a sustainable hybrid model has been constructed. With the proposed hybrid model, requirements prioritization in software development has been controlled effectively, reducing the failure risks and increasing the overall benefit and success rate. The success of the proposed hybrid approach is verified with two software case studies attaining satisfactory results and improving the organization's productivity by incorporating pivotal software requirements on which all the stakeholders agree. Furthermore, an automated approach will be developed by implementing the proposed approach to benefit from human–machine collaboration, improving user satisfaction by incorporating end-user opinions effectively and timely. [ABSTRACT FROM AUTHOR]

In software engineering, composition is the way to reuse existing work. In component-based development (CBD), a number of component models are defined with an emphasis on composition mechanisms for components. With respect to components, current component models can be categorised into three main groups where components are: (i) objects, (ii) architectural units and (iii) encapsulated components. This paper presents a comparison of system construction in these three categories of component models and concludes selecting the X-MAN component model (X-MAN) from the third category for its edge over other models because of its exogenous composition connectors. However, because of the limitations of X-MAN, the use of this component model at a wider scale is hindered. In this paper, we propose extended X-MAN component model (EX-MAN) which addresses the limitations of X-MAN. To demonstrate the EX-MAN semantics for system construction, we have developed a tool exogenous composition framework (ECF). We have described the concepts used in our work using a trivial bank example. To evaluate the feasibility of EX-MAN for system construction, using ECF (a related tool we have developed), we constructed the trivial bank example and also a more complex system, CoCoME, example. [ABSTRACT FROM AUTHOR]

Empirical research is playing a significant role in software engineering (SE), and it has been applied to evaluate software artifacts and technologies. There have been a great number of empirical research articles published recently. There is also a large research community in empirical software engineering (ESE). In this paper, we identify both the overall landscape and detailed implementations of ESE, and investigate frequently applied empirical methods, targeted research purposes, used data sources, and applied data processing approaches and tools in ESE. The aim is to identify new trends and obtain interesting observations of empirical software engineering across different sub-fields of software engineering. We conduct a mapping study on 538 selected articles from January 2013 to November 2017, with four research questions. We observe that the trend of applying empirical methods in software engineering is continuously increasing and the most commonly applied methods are experiment, case study and survey. Moreover, open source projects are the most frequently used data sources. We also observe that most of researchers have paid attention to the validity and the possibility to replicate their studies. These observations are carefully analyzed and presented as carefully designed diagrams. We also reveal shortcomings and demanded knowledge/strategies in ESE and propose recommendations for researchers. [ABSTRACT FROM AUTHOR]

Predicting software faults at the primary stage is a challenging role for software engineers and tech industries. During the development of software projects, it is necessary to predict the number of probable faults to have occurred on software rather than detecting whether the software modules are faulty or not. Discovering the number of expected faults helps software professionals to develop more reliable and high-quality software systems. However, the prediction model's performance gets affected while dealing with complicated software projects with increased cost factors such as time, effort, and resources. Therefore, to address the issue associated with handling complex software projects, a novel weighted dual cross-recurrent network-based levy sparrow search (WDCRN-LSS) model is proposed in this paper. The WDCRN-LSS approach by learning the data features with optimal hyperparameters accurately predicts the expected software faults in an earlier phase. Here, 17 PROMISE datasets containing 20 features each are utilized as input data for the proposed WDCRN-LSS model. The data inconsistencies are eliminated and then transformed to a suitable format for training through normalization, data transformation, and label encoding procedures. The preprocessed data are then trained using the proposed WDCRN-LSS model for the prediction of the expected number of software faults in the projects. With the excellent learning capability of feature representations, the proposed WDCRN-LSS model predicts software faults on upcoming/under-development software projects precisely. Thus, the proposed WDCRN-LSS model enhances software quality and minimizes cost factors such as time, resources, and effort that are depleted in developing software. The proposed WDCRN-LSS model's efficiency is investigated by utilizing evaluation measures namely error rate, precision, recall, F1-measure, the area under the curve, accuracy, and specificity. The experimental result manifests the efficiency of the proposed WDCRN-LSS model with a software fault detection accuracy of about 98.1%. [ABSTRACT FROM AUTHOR]

The availability of open source assets for almost all imaginable domains has led the software industry to opportunistic design—an approach in which people develop new software systems in an ad hoc fashion by reusing and combining components that were not designed to be used together. In this paper we investigate this emerging approach. We demonstrate the approach with an industrial example in which Node.js modules and various subsystems are used in an opportunistic way. Furthermore, to study opportunistic reuse as a phenomenon, we present the results of three contextual interviews and a survey with reuse practitioners to understand to what extent opportunistic reuse offers improvements over traditional systematic reuse approaches. [ABSTRACT FROM AUTHOR]

Empirical studies, often in the form of controlled experiments, have been widely adopted in software engineering research as a way to evaluate the merits of new software engineering tools. However, controlled experiments involving human participants actually using new tools are still rare, and when they are conducted, some have serious validity concerns. Recent research has also shown that many software engineering researchers view this form of tool evaluation as too risky and too difficult to conduct, as they might ultimately lead to inconclusive or negative results. In this paper, we aim both to help researchers minimize the risks of this form of tool evaluation, and to increase their quality, by offering practical methodological guidance on designing and running controlled experiments with developers. Our guidance fills gaps in the empirical literature by explaining, from a practical perspective, options in the recruitment and selection of human participants, informed consent, experimental procedures, demographic measurements, group assignment, training, the selecting and design of tasks, the measurement of common outcome variables such as success and time on task, and study debriefing. Throughout, we situate this guidance in the results of a new systematic review of the tool evaluations that were published in over 1,700 software engineering papers published from 2001 to 2011. [ABSTRACT FROM AUTHOR]

This paper introduces a nature-inspired optimized algorithm called modified moth-flame optimization (MMFO) for usability feature selection. To determine quality of software usability plays a significant role. This model contains various usability factors that are divided into several features, which have some characteristics, thus making a hierarchical model. Here, the authors have introduced MMFO (Modified Moth-flame optimization algorithm) for the selection of usability features to get an optimal solution MMFO is an extension of moth-flame optimization algorithm (MFO), which is based on the navigation method of moths called transverse orientation and to the best of our knowledge; this algorithm is introduced in software engineering practices. The selected features and accuracy of proposed MMFO is compared with the original MFO and other related optimization techniques. The results shows that the proposed nature-inspired optimization algorithm outperforms the other related optimizers as it generates a fewer number of selected features and having low accuracy. [ABSTRACT FROM AUTHOR]

Context: Code-free software similarity detection techniques have been used to support different software engineering tasks, including clustering mobile applications (apps). The way of measuring similarity may affect both the efficiency and quality of clustering solutions. However, there has been no previous comparative study of feature extraction methods used to guide mobile app clustering. Objective: In this paper, we investigate different techniques to compute the similarity of apps based on their textual descriptions and evaluate their effectiveness using hierarchical agglomerative clustering. Method: To this end we carry out an empirical study comparing five different techniques, based on topic modelling and keyword feature extraction, to cluster 12,664 apps randomly sampled from the Google Play App Store. The comparison is based on three main criteria: silhouette width measure, human judgement and execution time. Results: The results of our study show that using topic modelling, in addition to collocation-based and dependency-based feature extractors perform similarly in detecting app-feature similarity. However, dependency-based feature extraction performs better than any other in finding application domain similarity (ρ = 0.7,p − value < 0.01). Conclusions: Current categorisation in the app store studied does not exhibit a good classification quality in terms of the claimed feature space. However, a better quality can be achieved using a good feature extraction technique and a traditional clustering method. [ABSTRACT FROM AUTHOR]

Software benchmarks are only as good as the performance measurements they yield. Unstable benchmarks show high variability among repeated measurements, which causes uncertainty about the actual performance and complicates reliable change assessment. However, if a benchmark is stable or unstable only becomes evident after it has been executed and its results are available. In this paper, we introduce a machine-learning-based approach to predict a benchmark's stability without having to execute it. Our approach relies on 58 statically-computed source code features, extracted for benchmark code and code called by a benchmark, related to (1) meta information, e.g., lines of code (LOC), (2) programming language elements, e.g., conditionals or loops, and (3) potentially performance-impacting standard library calls, e.g., file and network input/output (I/O). To assess our approach's effectiveness, we perform a large-scale experiment on 4,461 Go benchmarks coming from 230 open-source software (OSS) projects. First, we assess the prediction performance of our machine learning models using 11 binary classification algorithms. We find that Random Forest performs best with good prediction performance from 0.79 to 0.90, and 0.43 to 0.68, in terms of AUC and MCC, respectively. Second, we perform feature importance analyses for individual features and feature categories. We find that 7 features related to meta-information, slice usage, nested loops, and synchronization application programming interfaces (APIs) are individually important for good predictions; and that the combination of all features of the called source code is paramount for our model, while the combination of features of the benchmark itself is less important. Our results show that although benchmark stability is affected by more than just the source code, we can effectively utilize machine learning models to predict whether a benchmark will be stable or not ahead of execution. This enables spending precious testing time on reliable benchmarks, supporting developers to identify unstable benchmarks during development, allowing unstable benchmarks to be repeated more often, estimating stability in scenarios where repeated benchmark execution is infeasible or impossible, and warning developers if new benchmarks or existing benchmarks executed in new environments will be unstable. [ABSTRACT FROM AUTHOR]

Business intelligence (BI) is perceived as a critical activity for organizations and is increasingly discussed in requirements engineering (RE). RE can contribute to the successful implementation of BI systems by assisting the identification and analysis of such systems' requirements and the production of the specification of the system to be. Within RE for BI systems, we focus in this paper on the following questions: (i) how the expectations of a BI system's stakeholders can be translated into accurate BI requirements, and (ii) how do we operationalize specifically these requirements in a system specification? In response, we define elicitation axes for the documentation of BI-specific requirements, give a list of six BI entities that we argue should be accounted for to operationalize business monitoring, and provide notations for the modeling of these entities. We survey important contributions of BI to define elicitation axes, adapt existing BI notations issued from RE literature, and complement them with new BI-specific notations. Using the i* framework, we illustrate the application of our proposal using a real-world case study. [ABSTRACT FROM AUTHOR]

The promise of Self-Service Business Intelligence (BI) is its ability to give business users access to selection, analysis, and reporting tools without requiring intervention from IT. This is essential if BI is to maximize its contribution by radically transforming how people make decisions. However, while some progress has been made through tools such as SAS Enterprise Miner, IBM SPSS Modeler, and RapidMiner, analytical modeling remains firmly in the domain of IT departments and data scientists. The development of tools that mitigate the need for modeling expertise remains the “missing link” in self-service BI, but prior attempts at developing modeling languages for non-technical audiences have not been widely implemented. By introducing a structured methodology for model formulation specifically designed for practitioners, this paper fills the unmet need to bring model-building to a mainstream business audience. The paper also shows how to build a dimensional Model Management Warehouse that supports the proposed methodology, and demonstrates the viability of this approach by applying it to a problem faced by the Division of Fiscal and Actuarial Services of the US Department of Labor. The paper concludes by outlining several areas for future research. [ABSTRACT FROM AUTHOR]

In software engineering predictive modeling, early prediction of software modules or classes that possess high maintainability effort is a challenging task. Many prediction models are constructed to predict the maintainability of software classes or modules by applying various machine learning (ML) techniques. If the software modules or classes need high maintainability, effort would be reduced in a dataset, and there would be imbalanced data to train the model. The imbalanced datasets make ML techniques bias their predictions towards low maintainability effort or majority classes, and minority class instances get discarded as noise by the machine learning (ML) techniques. In this direction, this paper presents empirical work to improve the performance of software maintainability prediction (SMP) models developed with ML techniques using imbalanced data. For developing the models, the imbalanced data is pre-processed by applying data resampling methods. Fourteen data resampling methods, including oversampling, undersampling, and hybrid resampling, are used in the study. The study results recommend that the safe-level synthetic minority oversampling technique (Safe-Level-SMOTE) is a useful method to deal with the imbalanced datasets and to develop competent prediction models to forecast software maintainability. [ABSTRACT FROM AUTHOR]

The energy consumption of computer systems has become an important economic and environmental issue. Many researchers have focused on the energy consumption of hardware, but what about the software? Software energy consumption is widely adopted for Green computation of practical experimentation in research laboratories. But current researchers fail to build a consistent concept base for software energy consumption of critical applications. While branch coverage and concolic testing are very critical practices to validate the safety critical systems, very little effort is given to measure their energy consumption. The computation of the energy consumption of these techniques is an important issue in Green IT and Green Software Engineering. The contribution of this paper is to automate the computation and analysis of the energy consumption of the testing technique while enhancing the branch coverage using concolic testing. We implement our proposed automation framework in a tool, named Green Analysis of Branch Coverage Enhancement. The empirical study with forty Java programs and the evaluation results show that our developed tool achieves an average increase of 13.5 % in branch coverage. The average energy consumption of our automated tool is approximately 5.6 kJ to compute the branch coverage for all the forty experimental programs. [ABSTRACT FROM AUTHOR]

Fault localization is one of the most important and difficult tasks in the software debugging process. Therefore, several methods have been proposed to automate and improve this process. Mutation-based fault localization is one of the states of the art techniques that try to locate faults by executing different mutants of the faulty program. In addition to favorable results, it is along with a massive increase in mutation execution cost. In this paper, we propose a new mutation-based fault localization approach called SMBFL, that aim to reduce the execution cost by reducing the number of statements to be mutated. As fewer mutants execute with SMBFL, the whole process will become faster and the cost will decrease. SMBFL only examines the statements in the dynamic slice of the program under test. The statements that present in the dynamic slice have a direct effect on the execution of the program with the specified test case. In the SMBFL method, the suspiciousness score of program statements is measured based on the entropy of their mutants. The proposed formula, MuEn, determines the suspiciousness score based on the result of executing mutants of each statement of the program. SMBFL is evaluated during a series of tests. The results show a relative increase in the accuracy of fault localization, by an average of 14.2%, and a decrease in the execution time of the fault localization process, by an average of 24.3%. Finally, the MuEn formula applies the least execution overhead to the fault localization process. [ABSTRACT FROM AUTHOR]

In this paper, we base our research on a fictional collective programming scenario: A group of physically-distributed programmers try to collaboratively solve a programming problem in a web-based development environment, through a continually executing loop, consisting of three concurrent activities: exploration, integration, and feedback. In exploration, a programmer is freely to submit a sequence of gradually improved solutions until achieving a correct one. All programmers' latest submissions are integrated into a collective artifact through integration. And through feedback, any programmer who hasn't achieved a correct solution is continuously pushed with personalized feedback information from the collective artifact, to help the programmer improve her/his submission. In order to facilitate the realization of this fictional scenario, we narrow the target problems to those introductory programming problems, design a genetic algorithm to integrate a set of syntax-correct programs into a collective program dependence graph (CPDG), and propose an automatic feedback generation method based on the CPDG and a programmer's latest submission. The key idea is to generate feedback from mutual inspiration: Any programmer's submission (even not correct) may possess information that could provide inspiration for others. We evaluate the proposed approach through a set of simulated experiments, as well as a set of real experiments. The results show that our approach has a precision of 90% and a recall of 80% in randomly generated data sets on average, and a precision of 69% and a recall of 77% in real student submissions on average. [ABSTRACT FROM AUTHOR]

Context: The 'as code' suffix in infrastructure as code (IaC) refers to applying software engineering activities, such as version control, to maintain IaC scripts. Without the application of these activities, defects that can have serious consequences may be introduced in IaC scripts. A systematic investigation of the development anti-patterns for IaC scripts can guide practitioners in identifying activities to avoid defects in IaC scripts. Development anti-patterns are recurring development activities that relate with defective IaC scripts. Goal: The goal of this paper is to help practitioners improve the quality of infrastructure as code (IaC) scripts by identifying development activities that relate with defective IaC scripts. Methodology: We identify development anti-patterns by adopting a mixed-methods approach, where we apply quantitative analysis with 2,138 open source IaC scripts and conduct a survey with 51 practitioners. Findings: We observe five development activities to be related with defective IaC scripts from our quantitative analysis. We identify five development anti-patterns namely, 'boss is not around', 'many cooks spoil', 'minors are spoiler', 'silos', and 'unfocused contribution'. Conclusion: Our identified development anti-patterns suggest the importance of 'as code' activities in IaC because these activities are related to quality of IaC scripts. [ABSTRACT FROM AUTHOR]

This paper analyzes the phenomenon of software aging – namely, the gradual performance degradation and resource exhaustion in the long run – in the Android OS. The study intends to highlight if, and to what extent, devices from different vendors, under various usage conditions and configurations, are affected by software aging and which parts of the system are the main contributors. The results demonstrate that software aging systematically determines a gradual loss of responsiveness perceived by the user, and an unjustified depletion of physical memory. The analysis reveals differences in the aging trends due to the workload factors and to the type of running applications, as well as differences due to vendors' customization. Moreover, we analyze several system-level metrics to trace back the software aging effects to their main causes. We show that bloated Java containers are a significant contributor to software aging, and that it is feasible to mitigate aging through a micro-rejuvenation solution at the container level. [ABSTRACT FROM AUTHOR]

For several years, the software engineering research community used eye trackers to study program comprehension, bug localization, pair programming, and other software engineering tasks. Eye trackers provide researchers with insights on software engineers' cognitive processes, data that can augment those acquired through other means, such as on-line surveys and questionnaires. While there are many ways to take advantage of eye trackers, advancing their use requires defining standards for experimental design, execution, and reporting. We begin by presenting the foundations of eye tracking to provide context and perspective. Based on previous surveys of eye tracking for programming and software engineering tasks and our collective, extensive experience with eye trackers, we discuss when and why researchers should use eye trackers as well as how they should use them. We compile a list of typical use cases—real and anticipated—of eye trackers, as well as metrics, visualizations, and statistical analyses to analyze and report eye-tracking data. We also discuss the pragmatics of eye tracking studies. Finally, we offer lessons learned about using eye trackers to study software engineering tasks. This paper is intended to be a one-stop resource for researchers interested in designing, executing, and reporting eye tracking studies of software engineering tasks. [ABSTRACT FROM AUTHOR]

Finding and fixing buggy code is an important and cost-intensive maintenance task, and static analysis (SA) is one of the methods developers use to perform it. SA tools warn developers about potential bugs by scanning their source code for commonly occurring bug patterns, thus giving those developers opportunities to fix the warnings (potential bugs) before they release the software. Typically, SA tools scan for general bug patterns that are common to any software project (such as null pointer dereference), and not for project specific patterns. However, past research has pointed to this lack of customizability as a severe limiting issue in SA. Accordingly, in this paper, we propose an approach called Ammonia, which is based on statically analyzing changes across the development history of a project, as a means to identify project-specific bug patterns. Furthermore, the bug patterns identified by our tool do not relate to just one developer or one specific commit, they reflect the project as a whole and compliment the warnings from other SA tools that identify general bug patterns. Herein, we report on the application of our implemented tool and approach to four Java projects: Ant, Camel, POI, and Wicket. The results obtained show that our tool could detect 19 project specific bug patterns across those four projects. Next, through manual analysis, we determined that six of those change patterns were actual bugs and submitted pull requests based on those bug patterns. As a result, five of the pull requests were merged. [ABSTRACT FROM AUTHOR]

A recent research showed that mobile apps represent nowadays 75% of the whole usage of mobile devices. This means that the mobile user experience, while tied to many factors (e.g., hardware device, connection speed, etc.), strongly depends on the quality of the apps being used. With "quality" here we do not simply refer to the features offered by the app, but also to its non-functional characteristics, such as security, reliability, and performance. This latter is particularly important considering the limited hardware resources (e.g., memory) mobile apps can exploit. In this paper, we present the largest study at date investigating performance bugs in mobile apps. In particular, we (i) define a taxonomy of the types of performance bugs affecting Android and iOS apps; and (ii) study the survivability of performance bugs (i.e., the number of days between the bug introduction and its fixing). Our findings aim to help researchers and apps developers in building performance-bugs detection tools and focusing their verification and validation activities on the most frequent types of performance bugs. [ABSTRACT FROM AUTHOR]

Software repositories contain a plethora of useful information that can be used to enhance software projects. Prior work has leveraged repository data to improve many aspects of the software development process, such as, help extract requirement decisions, identify potentially defective code and improve maintenance and evolution. However, in many cases, project stakeholders are not able to fully benefit from their software repositories due to the fact that they need special expertise to mine their repositories. Also, extracting and linking data from different types of repositories (e.g., source code control and bug repositories) requires dedicated effort and time, even if the stakeholder has the expertise to perform such a task. Therefore, in this paper, we use bots to automate and ease the process of extracting useful information from software repositories. Particularly, we lay out an approach of how bots, layered on top of software repositories, can be used to answer some of the most common software development/maintenance questions facing developers. We perform a preliminary study with 12 participants to validate the effectiveness of the bot. Our findings indicate that using bots achieves very promising results compared to not using the bot (baseline). Most of the participants (90.0%) find the bot to be either useful or very useful. Also, they completed 90.8% of the tasks correctly using the bot with a median time of 40 seconds per task. On the other hand, without the bot, the participants completed 25.2% of the tasks with a median time of 240 seconds per task. Our work has the potential to transform the MSR field by significantly lowering the barrier to entry, making the extraction of useful information from software repositories as easy as chatting with a bot. [ABSTRACT FROM AUTHOR]

Logging is a common practice in software engineering. Prior research has investigated the characteristics of logging practices in system software (e.g., web servers or databases) as well as desktop applications. However, despite the popularity of mobile apps, little is known about their logging practices. In this paper, we sought to study logging practices in mobile apps. In particular, we conduct a case study on 1,444 open source Android apps in the F-Droid repository. Through a quantitative study, we find that although mobile app logging is less pervasive than server and desktop applications, logging is leveraged in almost all studied apps. However, we find that there exist considerable differences between the logging practices of mobile apps and the logging practices in server and desktop applications observed by prior studies. In order to further understand such differences, we conduct a firehouse email interview and a qualitative annotation on the rationale of using logs in mobile app development. By comparing the logging level of each logging statement with developers' rationale of using the logs, we find that all too often (35.4%), the chosen logging level and the rationale are inconsistent. Such inconsistency may prevent the useful runtime information to be recorded or may generate unnecessary logs that may cause performance overhead. Finally, to understand the magnitude of such performance overhead, we conduct a performance evaluation between generating all the logs and not generating any logs in eight mobile apps. In general, we observe a statistically significant performance overhead based on various performance metrics (response time, CPU and battery consumption). In addition, we find that if the performance overhead of logging is significantly observed in an app, disabling the unnecessary logs indeed provides a statistically significant performance improvement. Our results show the need for a systematic guidance and automated tool support to assist in mobile logging practices. [ABSTRACT FROM AUTHOR]

Evaluation of search engines relies on assessments of search results for selected test queries, from which we would ideally like to draw conclusions in terms of relevance of the results for general (e.g., future, unknown) users. In practice however, most evaluation scenarios only allow us to conclusively determine the relevance towards the particular assessor that provided the judgments. A factor that cannot be ignored when extending conclusions made from assessors towards users, is the possible disagreement on relevance, assuming that a single gold truth label does not exist. This paper presents and analyzes the predicted relevance model (PRM), which allows predicting a particular result's relevance for a random user, based on an observed assessment and knowledge on the average disagreement between assessors. With the PRM, existing evaluation metrics designed to measure binary assessor relevance, can be transformed into more robust and effectively graded measures that evaluate relevance towards a random user. It also leads to a principled way of quantifying multiple graded or categorical relevance levels for use as gains in established graded relevance measures, such as normalized discounted cumulative gain, which nowadays often use heuristic and data-independent gain values. Given a set of test topics with graded relevance judgments, the PRM allows evaluating systems on different scenarios, such as their capability of retrieving top results, or how well they are able to filter out non-relevant ones. Its use in actual evaluation scenarios is illustrated on several information retrieval test collections. [ABSTRACT FROM AUTHOR]

Software process improvement (SPI) is an instrument to increase the productivity of, and the quality of work, in software organizations. However, a majority of SPI frameworks are too extensive or provide guidance and potential improvement areas at a high level, indicating only the symptoms, not the causes. Motivated by the industrial need of two Swedish automotive companies to systematically uncover the underlying root causes of high-level improvement issues identified in an SPI project—assessing inter-departmental interactions in large-scale software systems development—this paper advances a root cause analysis (RCA) method building on Lean Six Sigma, called Flex-RCA. Flex-RCA is used to delve deeper into challenges identified to find root causes as a part of the evaluation and subsequent improvement activities. We also demonstrate and evaluate Flex-RCA's industrial applicability in a case study. An overall conclusion is that the use of Flex-RCA was successful, showing that it had the desired effect of both producing a broad base of causes on a high level and, more importantly, enabling an exploration of the underlying root causes. [ABSTRACT FROM AUTHOR]

When projects lack sufficient local data to make predictions, they try to transfer information from other projects. How can we best support this process? In the field of software engineering, transfer learning has been shown to be effective for defect prediction. This paper checks whether it is possible to build transfer learners for software effort estimation. We use data on 154 projects from 2 sources to investigate transfer learning between different time intervals and 195 projects from 51 sources to provide evidence on the value of transfer learning for traditional cross-company learning problems. We find that the same transfer learning method can be useful for transfer effort estimation results for the cross-company learning problem and the cross-time learning problem. It is misguided to think that: (1) Old data of an organization is irrelevant to current context or (2) data of another organization cannot be used for local solutions. Transfer learning is a promising research direction that transfers relevant cross data between time intervals and domains. [ABSTRACT FROM AUTHOR]

This paper presents the results of an empirical study aiming at comparing the support provided by ER and UML class diagrams during maintenance of data models. We performed one controlled experiment and two replications that focused on comprehension activities (the first activity in the maintenance process) and another controlled experiment on modification activities related to the implementation of given change requests. The results achieved were analyzed at a fine-grained level aiming at comparing the support given by each single building block of the two notations. Such an analysis is used to identify weaknesses (i.e., building blocks not easy to comprehend) in a notation and/or can justify the need of preferring ER or UML for data modeling. The analysis revealed that the UML class diagrams generally provided a better support for both comprehension and modification activities performed on data models as compared to ER diagrams. Nevertheless, the former has some weaknesses related to three building blocks, i.e., multi-value attribute, composite attribute, and weak entity. These findings suggest that an extension of UML class diagrams should be considered to overcome these weaknesses and improve the support provided by UML class diagrams during maintenance of data models. [ABSTRACT FROM AUTHOR]

Given the challenges of testing at the system level, only a fully automated approach can really scale up to industrial real-time embedded systems (RTES). Our goal is to provide a practical approach to the model-based testing of RTES by allowing system testers, who are often not familiar with the system's design but are application domain experts, to model the system environment in such a way as to enable its black-box test automation. Environment models can support the automation of three tasks: the code generation of an environment simulator to enable testing on the development platform or without involving actual hardware, the selection of test cases, and the evaluation of their expected results (oracles). From a practical standpoint-and such considerations are crucial for industrial adoption-environment modeling should be based on modeling standards (1) that are at an adequate level of abstraction, (2) that software engineers are familiar with, and (3) that are well supported by commercial or open source tools. In this paper, we propose a precise environment modeling methodology fitting these requirements and discuss how these models can be used to generate environment simulators. The environment models are expressed using UML/MARTE and OCL, which are international standards for real-time systems and constraint modeling. The presented techniques are evaluated on a set of three artificial problems and on two industrial RTES. [ABSTRACT FROM AUTHOR]

This paper is about understanding the nature of bug fixing by analyzing thousands of bug fix transactions of software repositories. It then places this learned knowledge in the context of automated program repair. We give extensive empirical results on the nature of human bug fixes at a large scale and a fine granularity with abstract syntax tree differencing. We set up mathematical reasoning on the search space of automated repair and the time to navigate through it. By applying our method on 14 repositories of Java software and 89,993 versioning transactions, we show that not all probabilistic repair models are equivalent. [ABSTRACT FROM AUTHOR]

Companies are interested in knowing how users experience and perceive their products. Quality of Experience (QoE) is a measurement that is used to assess the degree of delight or annoyance in experiencing a software product. To assess QoE, we have used a feedback tool integrated into a software product to ask users about their QoE ratings and to obtain information about their rationales for good or bad QoEs. It is known that requests for feedback may disturb users; however, little is known about the subjective reasoning behind this disturbance or about whether this disturbance negatively affects the QoE of the software product for which the feedback is sought. In this paper, we present a mixed qualitative-quantitative study with 35 subjects that explore the relationship between feedback requests and QoE. The subjects experienced a requirement-modeling mobile product, which was integrated with a feedback tool. During and at the end of the experience, we collected the users’ perceptions of the product and the feedback requests. Based on the users’ rational for being disturbed by the feedback requests, such as “early feedback,” “interruptive requests,” “frequent requests,” and “apparently inappropriate content,” we modeled feedback requests. The model defines feedback requests using a set of five-tuple variables: “task,” “timing” of the task for issuing the feedback requests, user’s “expertise-phase” with the product, the “frequency” of feedback requests about the task, and the “content” of the feedback request. Configuration of these parameters might drive the participants’ perceived disturbances. We also found that the disturbances generated by triggering user feedback requests have negligible impacts on the QoE of software products. These results imply that software product vendors may trust users’ feedback even when the feedback requests disturb the users. [ABSTRACT FROM AUTHOR]

Cross-project defect prediction (CPDP) uses the labeled data from external source software projects to compensate the shortage of useful data in the target project, in order to build a meaningful classification model. However, the distribution gap between software features extracted from the source and the target projects may be too large to make the mixed data useful for training. In this paper, we propose a cluster-based novel method FeSCH (Feature Selection Using Clusters of Hybrid-Data) to alleviate the distribution differences by feature selection. FeSCH includes two phases. The feature clustering phase clusters features using a density-based clustering method, and the feature selection phase selects features from each cluster using a ranking strategy. For CPDP, we design three different heuristic ranking strategies in the second phase. To investigate the prediction performance of FeSCH, we design experiments based on real-world software projects, and study the effects of design options in FeSCH (such as ranking strategy, feature selection ratio, and classifiers). The experimental results prove the effectiveness of FeSCH. Firstly, compared with the state-of-the-art baseline methods, FeSCH achieves better performance and its performance is less affected by the classifiers used. Secondly, FeSCH enhances the performance by effectively selecting features across feature categories, and provides guidelines for selecting useful features for defect prediction. [ABSTRACT FROM AUTHOR]

Software intelligent development has become one of the most important research trends in software engineering. In this paper, we put forward two key concepts - intelligent development environment (IntelliDE) and software knowledge graph - for the first time. IntelliDE is an ecosystem in which software big data are aggregated, mined and analyzed to provide intelligent assistance in the life cycle of software development. We present its architecture and discuss its key research issues and challenges. Software knowledge graph is a software knowledge representation and management framework, which plays an important role in IntelliDE. We study its concept and introduce some concrete details and examples to show how it could be constructed and leveraged. [ABSTRACT FROM AUTHOR]

This paper proposes an explicit definition of green software requirements and a tool to support their evaluation . The proposed evaluation tool describes the green efficiency by considering the energy consumption as the main aspect to be studied during the development stage. This approach consists of building a multiple regression model, by using a supervised learning algorithm, in order to reproduce the energy consumption pattern of devices at different workload circumstances. The energy consumption model is then deployed to estimate the impact of software applications based on their resource usage. Our work has been validated on desktop and mobile devices. The experiments show the effectiveness of the proposed energy profiling tool that provided relevant information on the energy consumption of software applications. [ABSTRACT FROM AUTHOR]

In software engineering, the planning and budgeting stages of a software project are of great importance to all stakeholders, including project managers as well as clients. The estimated costs and scheduling time needed to develop any software project before and/or during startup form the basis of a project's success. The main objective of soft- ware estimation techniques is to determine the actual effort and/or time required for project development. The use of machine learning methods to address the estimation problem has, in general, proven remarkably successful for many engineering problems. In this study, a fully connected neural network (FCNN) model and a metaheuristic, gray wolf optimizer (GWO), called GWO-FC, is proposed to tackle the software development effort estimation (SEE) problem. The GWO is integrated with FCNN to optimize the FCNN parameters in order to enhance the accuracy of the obtained results by improving the FCNN's ability to explore the parameter search field and avoid falling into local optima. The proposed technique was evaluated utilizing various benchmark SEE datasets. Furthermore, various recent algorithms from the literature were employed to verify the GWO-FC performance. In terms of accuracy, comparative outcomes reveal that the GWO-FC performs better than other methods in most datasets and evaluation criteria. Experimental outcomes reveal the strong potential of the GWO-FC method to achieve reliable estimation results. [ABSTRACT FROM AUTHOR]

Large-scale software applications are complex systems that involve a myriad of different concerns. Ideally, these concerns should be organized into separated and different modules, but often some of these concerns overlap and crosscut each other. Such a situation is problematic, as concerns are tangled and scattered into different modules; thus, design and source code become difficult to produce and maintain. The Modularity community has been addressing crosscutting concerns by developing techniques based on separation of concerns. This separation must be done as early as possible during software construction to obtain a more modular and consequently better maintainable software, where evolution is performed with less effort and the possibility of introducing unforeseen mistakes is minimal. In this paper, we propose a strategy to identify crosscutting concerns at requirements level, i.e., at early stages in the software development process, by using the Language Extended Lexicon. [ABSTRACT FROM AUTHOR]