Context: Open-source software (OSS) development is often studied as a decentralized process driven by technical goals. However, mature OSS projects operate under external constraints such as security advisories, release deadlines, and ecosystem dependencies. These pressures shape technical decisions and also communication patterns among contributors, including emotional expression. Objective: This study investigates how emotional expression in OSS projects varies across different types of repositories, evolves over time, and relates to the activity of top contributors. The goal is to assess whether emotional dynamics are shaped more by project function than by technical domain or project size. Methods: We analyzed issue comments from 14 OSS repositories spanning over ten years. A transformer-based classifier was used to detect emotions. Emotional patterns were quantified using a composite Emotional Index, and contextual activity. Contributor roles were assessed using a Contribution Index combining code activity, discussion engagement, and sustained involvement. Analyses were conducted at the repository, temporal, and contributor levels. Results: The four most frequent emotions across all repositories were gratitude, curiosity, confusion, and approval. Emotional patterns tend to cluster by functional role rather than technical domain, with repositories converging toward stable emotional profiles over time. High-impact contributors show distinct expression patterns that reflect their role and stage of engagement. Conclusion: Emotional expression in OSS projects follows recurring patterns linked to project function, contributor roles, and maturity. These findings can help anticipate communication challenges during project evolution and support interaction strategies among contributor groups with differing emotional tendencies.

NASA collects vast amounts of problem data for space projects, which includes not only descriptions of defects but also enhancements and other issue reports. The growing complexity of Flight Software has led to an increase in the volume of problem reports, presenting both opportunities and challenges in data analysis. This paper explores AI-based solutions for classifying software issue reports in NASA’s spacecraft control systems. In particular, we aim to develop an accurate classifier for identifying bug tickets, building on previous research in automated issue labeling. We conduct a benchmark study for comparing various language models and provide insights on their performance and deployment costs, with the goal of improving issue classification for NASA’s growing software complexity. Based on our empirical results, we provide empirically-driven guidelines on how to address the tradeoff between the need for manual labeling of training data and the computational costs associated with the on-premise deployment of LLMs that could be used in a zero-shot setting.

Developers experience a wide range of emotions while creating software. Being able to identify the causes of one’s own and peers’ emotions can equip developers with the ability to regulate their behavior to restore positive moods and productivity. In this article, we investigate to what extent self-monitoring of emotions can enhance agile retrospective meetings by improving the emotion awareness of participants. To this aim, we conducted a controlled experiment involving three software development teams involving two student teams and one professional developers team. The experimental design involves the collection of biometrics and self-reported information about emotions, which are then visualized before the retrospective meetings to inform discussion using EmoVizPhy, a tool that we designed and implemented for this aim. While students found that self-monitoring helped them recall significant emotional episodes, leading to more meaningful contributions during retrospectives, professional developers perceived limited benefits from this practice. Furthermore, based on the analysis of corrective actions identified by the participants during the study, we hypothesize that self-monitoring of emotions through EmoVizPhy may play a valuable role in facilitating the consolidation of new agile teams for which roles and collaboration dynamics are still being defined.

Background. The widespread adoption of hybrid work following the COVID-19 pandemic has fundamentally transformed software development practices, introducing new challenges in communication and collaboration as organizations transition from traditional office-based structures to flexible working arrangements. This shift has established a new organizational norm where even traditionally office-first companies now embrace hybrid team structures. While remote participation in meetings has become commonplace in this new environment, it may lead to isolation, alienation, and decreased engagement among remote team members. Aims. This study aims to identify and characterize engagement patterns in hybrid meetings through objective measurements, focusing on the differences between co-located and remote participants. Method. We studied professionals from three software companies over several weeks, employing a multimodal approach to measure engagement. Data were collected through self-reported questionnaires and physiological measurements using biometric devices during hybrid meetings to understand engagement dynamics. Results. The regression analyses revealed comparable engagement levels between onsite and remote participants, though remote participants show lower engagement in long meetings regardless of participation mode. Active roles positively correlate with higher engagement, while larger meetings and afternoon sessions are associated with lower engagement. Conclusions. Our results offer insights into factors associated with engagement and disengagement in hybrid meetings, as well as potential meeting improvement recommendations. These insights are potentially relevant not only for software teams but also for knowledge-intensive organizations across various sectors facing similar hybrid collaboration challenges.

The gaming industry has witnessed remarkable growth in recent years, attracting millions of people who engage in its products both as a hobby and for professional purposes (e.g., e-sports). Video games are software products that have a unique and fundamental requirement: They must be engaging. Previous research introduced approaches aimed at measuring engagement, some of which specifically designed for video games. Such approaches could be useful for practitioners since they can be adopted on the large collection of gameplay videos daily published on platforms such as Twitch and YouTube to allow developers to monitor players’ engagement and detect areas in which it is low. Such specialized approaches have been evaluated on datasets in which the engagement was manually assessed by external evaluators based on the face of the player (we call it perceived engagement). We still do not know whether such approaches can capture the real engagement of players. Also, it is unclear to what extent practitioners would be willing to adopt such approaches in practice. In this paper, we provide two contributions. First, we ran an experiment with human 40 players aimed at defining a dataset of gameplay sessions in which participants self-reported their real engagement after every minute. We captured both their face and the gameplay. Based on this data, we compared state-of-the-art machine learning-based approaches to detect lowly engaging sessions. Our results show that the best model correctly classifies engagement in 74.7% of the cases and ranks video games in terms of their real engagement very similarly to how players would rank them (Spearman ρ = 0.833). Second, to assess the practicality of adopting such approaches in an industrial setting, we conducted two semi-structured interviews with senior game developers, who provided generally positive feedback and interesting insights for future developments.

Abstract Self-Admitted Technical Debt, or SATD, is a self-admission of technical debt present in a software system. The presence of SATD in software systems negatively affects developers, therefore, managing and addressing SATD is crucial for software engineering. To effectively manage SATD, developers need to estimate its priority and assess the effort required to fix the described technical debt. About a quarter of descriptions of SATD in software systems express some form of negativity or negative emotions when describing technical debt. In this paper, we report on an experiment conducted with 59 respondents to study whether negativity expressed in the description of SATD actually affects the prioritization of SATD. The respondents are a mix of professional developers and students, and in the experiment, we asked participants to prioritize four vignettes: two expressing negativity and two expressing neutral sentiment. To ensure the vignettes were realistic, they were based on existing SATD extracted from a dataset. We find that negativity causes between one-third and half of developers to prioritize SATD in which negativity is expressed as having more priority. Developers affected by negativity when prioritizing SATD are twice as likely to increase their estimation of urgency and 1.5 times as likely to increase their estimation of importance and effort for SATD compared to the likelihood of decreasing these prioritization scores. Our findings show how developers actively use negativity in SATD to determine how urgently a particular instance of technical debt should be addressed. However, our study also describes a gap in the actions and belief of developers. Even if 33% to 50% use negativity to prioritize SATD, 67% of developers believe that using negativity as a proxy for priority is unacceptable. Therefore, we would not recommend using negativity as a proxy for priority. However, we also recognize it might be unavoidable that negativity is expressed by developers to describe technical debt.

The diffusion of generative AI, specifically Large Language Models (LLMs), is profoundly affecting Software Engineering. Thanks to their unprecedented potential for disruptive changes, which mainly reside in their ability to reduce the need for large-scale training data for new tasks and to lower the technical entry barrier, these technologies offer the enormous opportunity to accelerate and enhance software engineering research and practice. Nevertheless, concerns also emerge related to the risks associated to poor results and indiscriminate use. In this evolving landscape, it becomes crucial to assess the opportunities and challenges posed by these emerging technologies. In this talk, I will reflect on the role of research in the era of AI in the hope of triggering a discussion on the shift in paradigm for empirical software engineering.

QualAI is a two-year project aimed at defining a set of recommenders to continuously monitor, assess, and improve the quality of AI-based systems, with a particular focus on machine learning (ML) applications. We will develop recommenders for the quality assurance of both data and ML models to enable practitioners to mitigate technical debt. Special attention will be paid to communication challenges that may arise in hybrid teams comprising data scientists and software developers. This paper presents the project outline, provides an executive summary of the research activities, outlines the expected project outcomes, and reports the results obtained to date.

Issue labeling is a crucial task for the effective management of software projects. To date, several approaches have been put forth for the automatic assignment of labels to issue reports. In particular, supervised approaches based on the fine-tuning of BERT-like language models have been proposed, achieving state-of-the-art performance. More recently, decoder-only models such as GPT have become prominent in SE research due to their surprising capabilities to achieve state-of-the-art performance even for tasks they have not been trained for. To the best of our knowledge, GPT-like models have not been applied yet to the problem of issue classification, despite the promising results achieved for many other software engineering tasks. In this paper, we investigate to what extent we can leverage GPT-like LLMs to automate the issue labeling task. Our results demonstrate the ability of GPT-like models to correctly classify issue reports in the absence of labeled data that would be required to fine-tune BERT-like LLMs.

Abstract Sentiment analysis has been used to study aspects of software engineering, such as issue resolution, toxicity, and self-admitted technical debt. To address the peculiarities of software engineering texts, sentiment analysis tools often consider the specific technical lingo practitioners use. To further improve the application of sentiment analysis, there have been two recommendations: Using pre-trained transformer models to classify sentiment and replacing non-natural language elements with meta-tokens. In this work, we benchmark five different sentiment analysis tools (two pre-trained transformer models and three machine learning tools) on 2 gold-standard sentiment analysis datasets. We find that pre-trained transformers outperform the best machine learning tool on only one of the two datasets, and that even on that dataset the performance difference is a few percentage points. Therefore, we recommend that software engineering researchers should not just consider predictive performance when selecting a sentiment analysis tool because the best-performing sentiment analysis tools perform very similarly to each other (within 4 percentage points). Meanwhile, we find that meta-tokenization does not improve the predictive performance of sentiment analysis tools. Both of our findings can be used by software engineering researchers who seek to apply sentiment analysis tools to software engineering data.

Capturing users’ engagement is crucial for gathering feedback about the features of a software product. In a market-driven context, current approaches to collecting and analyzing users’ feedback are based on techniques leveraging information extracted from product reviews and social media. These approaches are hardly applicable in contexts where online feedback is limited, as for the majority of apps, and software in general. In such cases, companies need to resort to face-to-face interviews to get feedback on their products. In this article, we propose to utilize biometric data, in terms of physiological and voice features, to complement product feedback interviews with information about the engagement of the user on product-relevant topics. We evaluate our approach by interviewing users while gathering their physiological data (i.e., biofeedback ) using an Empatica E4 wristband, and capturing their voice through the default audio-recorder of a common laptop. Our results show that we can predict users’ engagement by training supervised machine learning algorithms on biofeedback and voice data, and that voice features alone can be sufficiently effective. The best configurations evaluated achieve an average F1 ∼ 70% in terms of classification performance, and use voice features only. This work is one of the first studies in requirements engineering in which biometrics are used to identify emotions. Furthermore, this is one of the first studies in software engineering that considers voice analysis. The usage of voice features can be particularly helpful for emotion-aware feedback collection in remote communication, either performed by human analysts or voice-based chatbots, and can also be exploited to support the analysis of meetings in software engineering research.

Reflecting on the limitations of a study is a crucial part of the research process. In software engineering studies, this reflection is typically conveyed through discussions of study limitations or threats to validity. In current practice, such discussions seldom provide sufficient insight to understand the rationale for decisions taken before and during the study, and their implications. We revisit the practice of discussing study limitations and threats to validity and identify its weaknesses. We propose to refocus this practice of self-reflection to a discussion centered on the notion of trade-offs . We argue that documenting trade-offs allows researchers to clarify how the benefits of their study design decisions outweigh the costs of possible alternatives. We present guidelines for reporting trade-offs in a way that promotes a fair and dispassionate assessment of researchers’ work.

As researchers today, we are witnessing a fundamental change in our technologically-enabled world due to the advent and diffusion of highly disruptive technologies such as generative Artificial Intelligence (AI), Augmented Reality (AR) and Virtual Reality (VR). In particular, software engineering has been profoundly affected by the transformative power of disruptive innovations for decades, with a significant impact of technical advancements on social dynamics due to its socio-technical nature. In this article, we reflect on the importance of formulating and addressing research problems in software engineering through a socio-technical lens, thus ensuring a holistic understanding of the complex phenomena in this field. We propose a research playbook with the aim of providing a guide to formulate compelling and socially relevant research questions and to identify the appropriate research strategies for empirical investigations, with an eye on the long-term implications of technologies or their use. We showcase how to apply the research playbook. Firstly, we show how it can be used retrospectively to reflect on a prior disruptive technology, Stack Overflow, and its impact on software development. Secondly, we show how it can be used to question the impact of two current disruptive technologies: AI and AR/VR. Finally, we introduce a specialized GPT model to support the researcher in framing future investigations. We conclude by discussing the broader implications of adopting the playbook for both researchers and practitioners in software engineering and beyond.

Knowing which parts of the source code will be defective can allow practitioners to better allocate testing resources. For this reason, many approaches have been proposed to achieve this goal. Most state-of-the-art predictive models rely on product and process metrics, i.e., they predict the defectiveness of a component by considering what developers did. However, there is still limited evidence of the benefits that can be achieved in this context by monitoring how developers complete a development task. In this paper, we present an empirical study in which we aim at understanding whether measuring human aspects on developers while they write code can help predict the introduction of defects. First, we introduce a new developer-based model which relies on behavioral, psychophysical, and control factors that can be measured during the execution of development tasks. Then, we run a controlled experiment involving 20 software developers to understand if our developer-based model is able to predict the introduction of bugs. Our results show that a developer-based model is able to achieve a similar accuracy compared to a state-of-the-art code-based model, i.e., a model that uses only features measured from the source code. We also observed that by combining the models it is possible to obtain the best results (84% accuracy).

Early identification of emotions of software developers can enable timely intervention in order to support developers' well-being and prevent burnout. We present a machine learning experiment aimed at recognizing emotions during programming tasks using wearable biometric sensors, tracking electrodermal activity and heart-related metrics. As a gold standard for supervised learning, we rely on a state-of-the-art tool for emotion recognition based on facial expression analysis. We design, implement and evaluate an approach that combines the output of two classifiers for neutral valence recognition and positive/negative polarity classification. Our findings suggest that biometric sensors in a wristband can be used to identify emotions whose recognition would otherwise need an intrusive webcam.

Abstract Self-Admitted Technical Debt (SATD) consists of annotations—typically, but not only, source code comments—pointing out incomplete features, maintainability problems, or, in general, portions of a program not-ready yet. The way a SATD comment is written, and specifically its polarity, may be a proxy indicator of the severity of the problem and, to some extent, of the priority with which it should be addressed. In this paper, we study the relationship between different types of SATD comments in source code and their polarity, to understand in which circumstances (and why) developers use negative or rather neutral comments to highlight an SATD. To address this goal, we combine a manual analysis of 1038 SATD comments from a curated dataset with a survey involving 46 professional developers. First of all, we categorize SATD content into its types. Then, we study the extent to which developers express negative sentiment in different types of SATD as a proxy for priority, and whether they believe this can be considered as an acceptable practice. Finally, we look at whether such annotations contain additional details such as bug references and developers’ names/initials. Results of the study indicate that SATD comments are mainly used for annotating poor implementation choices ( $\simeq $ ≃ 41%) and partially implemented functionality ( $\simeq $ ≃ 22%). The latter may depend from “waiting” for other features being implemented, and this makes SATD comments more negatives than in other cases. Around 30% of the survey respondents agree on using/interpreting negative sentiment as a proxy for priority, while 50% of them indicate that it would be better to discuss SATD on issue trackers and not in the source code. However, while our study indicates that open-source developers use links to external systems, such as bug identifiers, to annotate high-priority SATD, better tool support is required for SATD management.

Abstract Discussions is a new feature of GitHub for asking questions or discussing topics outside of specific Issues or Pull Requests. Before being available to all projects in December 2020, it had been tested on selected open source software projects. To understand how developers use this novel feature, how they perceive it, and how it impacts the development processes, we conducted a mixed-methods study based on early adopters of GitHub discussions from January until July 2020. We found that: (1) errors, unexpected behavior, and code reviews are prevalent discussion categories; (2) there is a positive relationship between project member involvement and discussion frequency; (3) developers consider GitHub Discussions useful but face the problem of topic duplication between Discussions and Issues; (4) Discussions play a crucial role in advancing the development of projects; and (5) positive sentiment in Discussions is more frequent than in Stack Overflow posts. Our findings are a first step towards data-informed guidance for using GitHub Discussions, opening up avenues for future work on this novel communication channel.

Opinion mining, sometimes referred to as sentiment analysis, has gained increasing attention in software engineering (SE) studies. SE researchers have applied opinion mining techniques in various contexts, such as identifying developers’ emotions expressed in code comments and extracting users’ critics toward mobile apps. Given the large amount of relevant studies available, it can take considerable time for researchers and developers to figure out which approaches they can adopt in their own studies and what perils these approaches entail. We conducted a systematic literature review involving 185 papers. More specifically, we present (1) well-defined categories of opinion mining-related software development activities, (2) available opinion mining approaches, whether they are evaluated when adopted in other studies, and how their performance is compared, (3) available datasets for performance evaluation and tool customization, and (4) concerns or limitations SE researchers might need to take into account when applying/customizing these opinion mining techniques. The results of our study serve as references to choose suitable opinion mining tools for software development activities and provide critical insights for the further development of opinion mining techniques in the SE domain.

Emotions are known to impact cognitive skills, thus influencing job performance. This is also true for software development, which requires creativity and problem-solving abilities. In this paper, we report the results of a field study involving professional developers from five different companies. We provide empirical evidence that a link exists between emotions and perceived productivity at the workplace. Furthermore, we present a taxonomy of triggers for developers’ positive and negative emotions, based on the qualitative analysis of participants’ self-reported answers collected through daily experience sampling. Finally, we experiment with a minimal set of non-invasive biometric sensors that we use as input for emotion detection. We found that positive emotional valence, neutral arousal, and high dominance are prevalent. We also found a positive correlation between emotional valence and perceived productivity, with a stronger correlation in the afternoon. Both social and individual breaks emerge as useful for restoring a positive mood. Furthermore, we found that a minimum set of non-invasive biometric sensors can be used as a predictor for emotions, provided that training is performed on an individual basis. While promising, our classifier performance is not yet robust enough for practical usage. Further data collection is required to strengthen the classifier, by also implementing individual fine-tuning of emotion models.

Self-Admitted Technical Debt (SATD) represents the admission, made through source code comments or other channels, of portions of a program being poorly implemented, containing provisional solutions or, in general, simply being not ready yet. To better understand developers' habits in SATD annotation, and possibly support their exploitation in tool support, this paper provides an in-depth analysis of the content provided in SATD comments, and the expressed sentiment. We manually inspect and classify 1038 instances from an existing dataset, grouping them along a taxonomy composed of 41 categories (of which 9 top-level ones), identifying their sentiment, and the presence of external references such as author names or issue IDs. Results of our study indicate that (i) the SATD content is crosscutting along life-cycle dimensions identified in previous work, (ii) comments related to functional problems or on-hold SATD are generally more negative than poor implementation choices or partially implemented functionality, and (iii) despite observations from previous literature, only a minority of SATD comments leverage external references.

Abstract Context Code review is a widely used technique of systematic examination of code changes which aims at increasing software quality. Code reviews provide several benefits for the project, including finding bugs, knowledge transfer, and assurance of adherence to project guidelines and coding style. However, code reviews have a major cost: they can delay the merge of the code change, and thus, impact the overall development process. This cost can be even higher if developers do not understand something, i.e., when developers faceconfusionduring the code review. Objective This paper studies the phenomenon ofconfusionin code reviews. Understanding confusion is an important starting point to help reducing the cost of code reviews and enhance the effectiveness of this practice, and hence, improve the development process. Method We conducted two complementary studies. The first one aimed at identifying the reasons for confusion in code reviews, its impacts, and the coping strategies developers use to deal with it. Then, we surveyed developers to identify the most frequently experienced reasons for confusion, and conducted a systematic mapping study of solutions proposed for those reasons in the scientific literature. Results From the first study, we build a framework with 30 reasons for confusion, 14 impacts, and 13 coping strategies. The results of the systematic mapping study shows 38 articles addressing the most frequent reasons for confusion. From those articles, we found 13 different solutions for confusion proposed in the literature, and five impacts were established related to the most frequent reasons for confusion. Conclusions Based on the solutions identified in the mapping study, or the lack of them, we propose an actionable guideline for developers on how to cope with confusion during code reviews; we also make several suggestions how tool builders can support code reviews. Additionally, we propose a research agenda for researchers studying code reviews.

Abstract Sentiment analysis methods have become popular for investigating human communication, including discussions related to software projects. Since general-purpose sentiment analysis tools do not fit well with the information exchanged by software developers, new tools, specific for software engineering (SE), have been developed. We investigate to what extent off-the-shelf SE-specific tools for sentiment analysis mitigate the threats to conclusion validity of empirical studies in software engineering, highlighted by previous research. First, we replicate two studies addressing the role of sentiment in security discussions on GitHub and in question-writing on Stack Overflow. Then, we extend the previous studies by assessing to what extent the tools agree with each other and with the manual annotation on a gold standard of 600 documents. We find that different SE-specific sentiment analysis tools might lead to contradictory results at a fine-grain level, when used off-the-shelf. Conversely, platform-specific tuning or retraining might be needed to take into account differences in platform conventions, jargon, or document lengths.

Sentiment analysis in social media is a popular task attracting the interest of the research community, also in recent evaluation campaigns of natural language processing tasks in several languages. We report on our experience in the organization of SENTIment POLarity Classification Task (SENTIPOLC), a shared task on sentiment classification of Italian tweets, proposed for the first time in 2014 within the Evalita evaluation campaign. We present the datasets-which include an enriched annotation scheme for dealing with the impact of figurative language on polarity-the evaluation methodology, and discuss the approaches and results of participating systems. We also offer a reflection on the open challenges of state-of-the-art systems for sentiment analysis of microblogging in Italian, as they emerge from a qualitative analysis of misclassified tweets. Finally, we provide an evaluation of the resources we have created, and share the lessons learned by running this task for two consecutive editions.

In open-source software (OSS), the design of usability is often influenced by the discussions among community members on platforms such as issue tracking systems (ITSs). However, digesting the rich information embedded in issue discussions can be a major challenge due to the vast number and diversity of the comments. We propose and evaluate ArguLens, a conceptual framework and automated technique leveraging an argumentation model to support effective understanding and consolidation of community opinions in ITSs. Through content analysis, we anatomized highly discussed usability issues from a large, active OSS project, into their argumentation components and standpoints. We then experimented with supervised machine learning techniques for automated argument extraction. Finally, through a study with experienced ITS users, we show that the information provided by ArguLens supported the digestion of usability-related opinions and facilitated the review of lengthy issues. ArguLens provides the direction of designing valuable tools for high-level reasoning and effective discussion about usability.

Developers experience a wide range of emotions during programming tasks, which may have an impact on job performance. In this paper, we present an empirical study aimed at (i) investigating the link between emotion and progress, (ii) understanding the triggers for developers' emotions and the strategies to deal with negative ones, (iii) identifying the minimal set of non-invasive biometric sensors for emotion recognition during programming tasks. Results confirm previous findings about the relation between emotions and perceived productivity. Furthermore, we show that developers' emotions can be reliably recognized using only a wristband capturing the electrodermal activity and heart-related metrics.

This paper describes the participation of a team from the University of Bari in the Decluttering Challenge organized in the scope of the DocGen2 workshop. We propose a supervised approach relying on a minimal set of non-textual features (length, overlapping between the comment text and the source code, code block type, tags, comment type) and classical textual features (bag-of-words). Our system ranked 2nd in the documentation decluttering task.

In this paper, we address the problem of using sentiment analysis tools 'off-the-shelf', that is when a gold standard is not available for retraining. We evaluate the performance of four SE-specific tools in a cross-platform setting, i.e., on a test set collected from data sources different from the one used for training. We find that (i) the lexicon-based tools outperform the supervised approaches retrained in a cross-platform setting and (ii) retraining can be beneficial in within-platform settings in the presence of robust gold standard datasets, even using a minimal training set. Based on our empirical findings, we derive guidelines for reliable use of sentiment analysis tools in software engineering.

Capturing users' engagement is crucial for gathering feedback about the features of a software product. In a market-driven context, current approaches to collect and analyze users' feedback are based on techniques leveraging information extracted from product reviews and social media. These approaches are hardly applicable in bespoke software development, or in contexts in which one needs to gather information from specific users. In such cases, companies need to resort to face-to-face interviews to get feedback on their products. In this paper, we propose to utilize biofeedback to complement interviews with information about the engagement of the user on the discussed features and topics. We evaluate our approach by interviewing users while gathering their biometric data using an Empatica E4 wristband. Our results show that we can predict users' engagement by training supervised machine learning algorithms on the biometric data. The results of our work can be used to facilitate the prioritization of product features and to guide the interview based on users' engagement.

Abstract Context As a novel coronavirus swept the world in early 2020, thousands of software developers began working from home. Many did so on short notice, under difficult and stressful conditions. Objective This study investigates the effects of the pandemic on developers’ wellbeing and productivity. Method A questionnaire survey was created mainly from existing, validated scales and translated into 12 languages. The data was analyzed using non-parametric inferential statistics and structural equation modeling. Results The questionnaire received 2225 usable responses from 53 countries. Factor analysis supported the validity of the scales and the structural model achieved a good fit (CFI = 0.961, RMSEA = 0.051, SRMR = 0.067). Confirmatory results include: (1) the pandemic has had a negative effect on developers’ wellbeing and productivity; (2) productivity and wellbeing are closely related; (3) disaster preparedness, fear related to the pandemic and home office ergonomics all affect wellbeing or productivity. Exploratory analysis suggests that: (1) women, parents and people with disabilities may be disproportionately affected; (2) different people need different kinds of support. Conclusions To improve employee productivity, software companies should focus on maximizing employee wellbeing and improving the ergonomics of employees’ home offices. Women, parents and disabled persons may require extra support.

Code comprehension has been recently investigated from physiological and cognitive perspectives using medical imaging devices. Floyd et al. (i.e., the original study) used fMRI to classify the type of comprehension tasks performed by developers and relate their results to their expertise. We replicate the original study using lightweight biometrics sensors. Our study participants-28 undergrads in computer science-performed comprehension tasks on source code and natural language prose. We developed machine learning models to automatically identify what kind of tasks developers are working on leveraging their brain-, heart-, and skin-related signals. The best improvement over the original study performance is achieved using solely the heart signal obtained through a single device (BAC 87%vs. 79.1%). Differently from the original study, we did not observe a correlation between the participants' expertise and the classifier performance (τ= 0.16, p= 0.31). Our findings show that lightweight biometric sensors can be used to accurately recognize comprehension opening interesting scenarios for research and practice.

Code review is a software quality assurance practice widely employed in both open source and commercial software projects to detect defects, transfer knowledge and encourage adherence to coding standards. Notwithstanding, code reviews can also delay the incorporation of a code change into a code base, thus slowing down the overall development process. Part of this delay is often a consequence of reviewers not understanding, becoming confused by, or being uncertain about the intention, behavior, or effect of a code change.We investigate the reasons and impacts of confusion in code reviews, as well as the strategies developers adopt to cope with confusion. We employ a concurrent triangulation strategy to combine the analyses of survey responses and of the code review comments, and build a comprehensive confusion framework structured along the dimensions of the review process, the artifact being reviewed, the developers themselves and the relation between the developer and the artifact. The most frequent reasons for confusion are the missing rationale, discussion of non-functional requirements of the solution, and lack of familiarity with existing code. Developers report that confusion delays the merge decision, decreases review quality, and results in additional discussions. To cope with confusion developers request information, improve familiarity with existing code, and discuss off-line. Based on the results, we provide a series of implications for tool builders, as well as insights and suggestions for researchers. The results of our work offer empirical justification for the need to improve code review tools to support developers facing confusion.

The role of sentiment analysis is increasingly emerging to study software developers' emotions by mining crowd-generated content within software repositories and information sources. With a few notable exceptions [1][5], empirical software engineering studies have exploited off-the-shelf sentiment analysis tools. However, such tools have been trained on non-technical domains and general-purpose social media, thus resulting in misclassifications of technical jargon and problem reports [2][4]. In particular, Jongeling et al. [2] show how the choice of the sentiment analysis tool may impact the conclusion validity of empirical studies because not only these tools do not agree with human annotation of developers' communication channels, but they also disagree among themselves.

During code review, developers request clarifications, suggest improvements, or ask for explanations about the rationale behind the implementation choices. We envision the emergence of tools to support developers during code review based on the automatic analysis of the argumentation structure and communicative intentions conveyed by developers' comments. As a preliminary step towards this goal, we conducted an exploratory case study by manually classifying 499 questions extracted from 399 Android code reviews to understand the real communicative intentions they convey. We observed that the majority of questions actually serve information seeking goals. Still, they represent less than half of the annotated sample, with other questions being used to serve a wider variety of developers' communication goals, including suggestions, request for action, and criticism. Based on our findings we formulate hypotheses on communicative intentions in code reviews that should be confirmed or rejected by follow-up studies.

Software developers experience and share a wide range of emotions throughout a rich ecosystem of communication channels. A recent trend that has emerged in empirical software engineering studies is leveraging sentiment analysis of developers' communication traces. We release a dataset of 4,800 questions, answers, and comments from Stack Overflow, manually annotated for emotions. Our dataset contributes to the building of a shared corpus of annotated resources to support research on emotion awareness in software development.

A recent research trend has emerged to identify developers' emotions, by applying sentiment analysis to the content of communication traces left in collaborative development environments. Trying to overcome the limitations posed by using off-the-shelf sentiment analysis tools, researchers recently started to develop their own tools for the software engineering domain. In this paper, we report a benchmark study to assess the performance and reliability of three sentiment analysis tools specifically customized for software engineering. Furthermore, we offer a reflection on the open challenges, as they emerge from a qualitative analysis of misclassified texts.1

Emotion recognition from biometrics is relevant to a wide range of application domains, including healthcare. Existing approaches usually adopt multi-electrodes sensors that could be expensive or uncomfortable to be used in real-life situations. In this study, we investigate whether we can reliably recognize high vs. low emotional valence and arousal by relying on noninvasive low cost EEG, EMG, and GSR sensors. We report the results of an empirical study involving 19 subjects. We achieve state-of-the-art classification performance for both valence and arousal even in a cross-subject classification setting, which eliminates the need for individual training and tuning of classification models.

Establishing trust between developers working atdistant sites facilitates team collaboration in distributed software development. While previous research has focused on how to build and spread trust in absence of direct, face-to-face communication, it has overlooked the effects of the propensity to trust, i.e., the trait of personality representing the individual disposition to perceive the others as trustworthy. In this study, we present a preliminary, quantitative analysis on how the propensity to trust affects the success of collaborations in a distributed project, where thesuccess is represented by pull requests whose code changes and contributions are successfully merged in the project's repository.

Code reviews are an important mechanism for assuring quality of source code changes. Reviewers can either add general comments pertaining to the entire change or pinpoint concerns or shortcomings about a specific part of the change using inline comments. Recent studies show that reviewers often do not understand the change being reviewed and its context.Our ultimate goal is to identify the factors that confuse code reviewers and understand how confusion impacts the efficiency and effectiveness of code review(er)s. As the first step towards this goal we focus on the identification of confusion in developers' comments. Based on an existing theoretical framework categorizing expressions of confusion, we manually classify 800 comments from code reviews of the Android project. We observe that confusion can be reasonably well-identified by humans: raters achieve moderate agreement (Fleiss' kappa 0.59 for the general comments and 0.49 for the inline ones). Then, for each kind of comment we build a series of automatic classifiers that, depending on the goals of the further analysis, can be trained to achieve high precision (0.875 for the general comments and 0.615 for the inline ones), high recall (0.944 for the general comments and 0.988 for the inline ones), or substantial precision and recall (0.696 and 0.542 for the general comments and 0.434 and 0.583 for the inline ones, respectively). These results motivate further research on the impact of confusion on the code review process. Moreover, other researchers can employ the proposed classifiers to analyze confusion in other contexts where software development-related discussions occur, such as mailing lists.

Emotional arousal increases activation and performance but may also lead to burnout in software development. We present the first version of a Software Engineering Arousal lexicon (SEA) that is specifically designed to address the problem of emotional arousal in the software developer ecosystem. SEA is built using a bootstrapping approach that combines word embedding model trained on issue-tracking data and manual scoring of items in the lexicon. We show that our lexicon is able to differentiate between issue priorities, which are a source of emotional activation and then act as a proxy for arousal. The best performance is obtained by combining SEA (428 words) with a previously created general purpose lexicon by Warriner et al. (13,915 words) and it achieves Cohen's d effect sizes up to 0.5.

In this paper, we describe the overall goals and expected contribution of the EmoQuest project. EmoQuest is a three-year multi-disciplinary research project whose main goal is to understand the role of emotions in social media-based knowledge sharing, specifically in online Question and Answer (Q&A) sites. The main research domain of EmoQuest is Computer Supported Cooperative Work (CSCW), with expected outputs in Human-Computer Interaction, Software Engineering, Linguistics, and Psychology.

Context: Recently, more and more developer communities are abandoning their legacy support forums, moving onto Stack Overflow. The motivations are diverse, yet they typically include achieving faster response time and larger visibility through the access to a modern and very successful infrastructure. One downside of migration, however, is that the history and the crowdsourced knowledge hosted at previous sites remain separated or even get lost if a community decides to abandon completely the legacy developer forum.

Recent research has shown that drivers of success in online question answering encompass presentation quality as well as temporal and social aspects. Yet, we argue that also the emotional style of a technical contribution influences its perceived quality. In this paper, we investigate how Stack Overflow users can increase the chance of getting their answer accepted. We focus on actionable factors that can be acted upon by users when writing an answer and making comments. We found evidence that factors related to information presentation, time and affect all have an impact on the success of answers.

We present the preliminary results of an ongoing research aimed at investigating the role of social media in the process of trust building, with particular attention to the case of small-medium enterprises (SME). Our findings show that social media contribute to increase the affective trust more than traditional websites. This result suggests that social media have the potential to enhance the business of SMEs other than large companies, by fostering the affective commitment of customers.

We present a qualitative analysis of the lexicon of dialogue acts: we explore the relationship between the communicative goal of an utterance and its affective lexicon as well as the salience of specific word classes for each speech act. Thought not constituting any deep understanding of the dialogue, automatic dialogue act labeling is a task that may be relevant for a wide range of applications in both human-computer and human-human interaction. The experiments described in this paper fit in the scope of a research study whose long-term goal is to build an unsupervised classifier that simply exploits the lexical semantics of utterances to automatically annotate dialogues with the proper speech acts.

The problem of implementing socially intelligent agents has been widely investigated in the field of both Embodied Conversational Agents (ECAs) and Social Robots that have the advantage of offering to people the possibility to relate with computer media at a social level. We focus our study on the recognition of the social response of users to embodied agents in the context of ambient intelligence. In this paper we describe how we extended a model for recognizing the social attitude in natural conversation from text by adding two additional knowledge sources: speech and gestures.

As far as interaction is concerned Ambient Intelligence (AmI) research emphasizes the need of natural and friendly interfaces for accessing services provided by the environment. In this paper we present the result of an experimental study aiming at understanding whether Embodied Conversational Agents (ECAs) and Social Robots may improve the naturalness and effectiveness of interaction by playing different roles when acting as interface between users and smart environment services. Results obtained so far show that ECAs seem to have a better evaluation than robots for information related tasks. On the other side, Social Robots are preferred for welcoming people and for guiding them in the smart environment, due to their possibility to move and to the perceived sense of presence. Moreover, the robot seems to elicit a more positive evaluation in terms of user experience.

When visiting cities as tourists, most of the times people do not make very detailed plans and, when choosing where to go and what to seem they tend to select the area with the major number of interesting facilities. Therefore, it would be useful to support the user choice with contextual information presentation, information clustering and comparative explanations of places of potential interest in a given area. In this paper we illustrate how MyMap, a mobile recommender system in the Tourism domain, generates comparative descriptions to support users in making decisions about what to see, among relevant objects of interest.

This paper describes our experience with the design, implementation and validation of a user model for adapting health promotion dialogs with ECAs to the attitude of users toward the agent. The model was conceived in agreement with the theory of social emotions in communication. It integrates a linguistic parser with a dynamic Bayesian network and was learnt from a corpus of data collected with a Wizard of Oz study