Context: Diversity can impact team communication, productivity, cohesiveness, and creativity. Analyzing the existing knowledge about diversity in open source software (OSS) projects can provide directions for future research and raise awareness about barriers and biases against underrepresented groups in OSS. Objective: This study aims to analyze the knowledge about minority groups in OSS projects. We investigated which groups were studied in the OSS literature, the study methods used, their implications, and their recommendations to promote the inclusion of minority groups in OSS projects. Method: To achieve this goal, we performed a systematic literature review study that analyzed 42papers that directly study underrepresented groups in OSS projects. Results: Most papers focus on gender (62.3%), while others like age or ethnicity are rarely studied. The neurodiversity dimension, have not been studied in the context of OSS. Our results also reveal that diversity in OSS projects faces several barriers but brings significant benefits, such as promoting safe and welcoming environments. Conclusion: Most analyzed papers adopt a myopic perspective that sees gender as strictly binary. Dimensions of diversity that affect how individuals interact and function in an OSS project, such as age, tenure, and ethnicity, have received very little attention.

Software testing is an important area in the Software Engineering domain, yet it faces significant gaps within Computer Science education. In that context, there is an even less addressed topic: internationalization (i18n) and localization (l10n) tests, which are essential for ensuring software quality in global markets, supporting multiple languages. A key challenge for both large and small companies is the onboarding of new testers without adequate skills, often resulting in insufficient real-world preparation. This paper proposes a tool-assisted training approach designed to enhance the proficiency of l10n and i18n testers through practical, hands-on exercises using real-world failure examples. The effectiveness of our approach was evaluated from two complementary perspectives: i) To assess the effectiveness of the training approach, a case study was conducted within a software industry training setting, comparing novice testers trained with our tool against those receiving conventional training. Results indicated a 150% improvement in fault identification and resolution for testers using the tool, underscoring its effectiveness in enhancing testing skills and overall software quality. ii) To evaluate the perceived usability of the tool developed to support the training activities, a System Usability Scale (SUS) questionnaire was given to five technical leaders responsible for training novice testers. The tool achieved a score of 94.5, positioning its usability between “excellent” and “best imaginable”. This paper highlights the tool's design, deployment context, and its potential for adoption by other practitioners, aiming to address the current gaps in i18n and l10n tester training, being a promising approach to be used in Software Engineering education.

ABSTRACT Context Reactive Programming (RP) provides powerful abstractions for managing asynchronous and event‐driven behaviors, but its APIs are often perceived as complex and difficult to use, particularly due to their reliance on functional programming concepts. Objective This study investigates the usability of two prominent JavaScript RP libraries, RxJS and Bacon.js, to identify common usability issues and suggest improvements. Method A mixed‐method evaluation was conducted. First, objective structural metrics were applied to assess the libraries' design. Then, a user‐centered study was performed involving programming tasks, a post‐task questionnaire based on the Cognitive Dimensions of Notation (CDN) framework, and follow‐up interviews. Results Both libraries exhibited moderate usability. Metrics revealed strengths in reusability and parameter design, while user studies highlighted challenges in learnability, error handling, and documentation. RxJS generally performed better in metrics, while Bacon.js had stronger task completion rates. Conclusion The findings suggest that despite their popularity, RP APIs can still hinder adoption due to usability issues. Improvements such as enhanced documentation, guided error‐handling strategies, and reduced operator complexity can significantly improve developer experience.

Time-bounded collaborative events attract people with different backgrounds to work in small teams to develop a project that addresses a particular problem in a very short amount of time. Previous research acknowledges that event participants have the opportunity to learn new things, meet people, and gain recognition, among other benefits. However, there are few studies exploring the relationship between these events and startups. Basically, these studies report that some projects developed during these events result in startups. This paper aims to explore how startup founders benefit from time-bounded events. We used a qualitative exploratory approach to collecting data through semi-structured interviews with 20 startup founders. The benefits cited by the interviewees include the development of new products, raising money, gaining visibility, and identifying opportunities for action, learning and networking. In particular, learning can be divided into many types, including learning about software development and business methodologies, new tools, and soft skills. Networking can benefit startups by allowing them to identify founders, partners, customers, and employees. Our results suggest that participation in time-bounded collaborative events helps startup founders to satisfy some of the needs of their startups. We conclude by presenting recommendations for event organizers.

Hackathons are time-bounded collaborative events that typically take between 1 and 3 days of intense teamwork to build prototypes usually in the form of software, aiming to specific challenges proposed by the organizers. These events became a widespread practice in the IT industry, in universities and in many other scenarios, as a result of a growing open-innovation trend in the last decade. Since the main deliverable of these events is a demonstrable version of an idea, such as early hardware or software prototypes, the short time frame requires participants to quickly understand the proposed challenge or even identify issues related to a given domain. To create solutions, teams follow an ad-hoc but effective design approach, that many times seems informal since the background of the participants is rather centered on technical aspects (e.g., web and mobile programming) and does not involve any training in design thinking.To understand this creative process, we conducted a set of 37 interviews with people from 16 countries, consisting of 32 hackathons winners and 5 hackathon organizers. We aimed to identify the design practices (i.e., processes and recurring design methods) that are applied by winners in these types of events. Also, we conducted a focus group with 8 people experienced in hackathons (participants and organizers) to discuss our findings. Our analysis revealed that although hackathon winners with IT background have no formal training in design thinking, they are aware of many design methods and typically follow a sequence of phases that involve divergent and convergent thinking to explore the problem space and propose alternatives in a solution space, which is the rationale behind design thinking. We derived a set of recommendations based on design strategies that seem to lead to successful hackathon participation. These recommendations can also be useful to organizers who intend to enhance the experience of newcomers in hackathons.

We present an approach for teaching introductory Scrum concepts through a playful online collaborative activity. It was conducted with 1st-semester students who never had any in-person contact and started their course under emergency online teaching during the Covid-19 pandemic. We adapted the Lego4Scrum approach and instead of plastic bricks, we combined an online whiteboard (Miro) with a communication tool (Discord) for teams.

Conventionally, callbacks and inversion of control have been the main tools to structure event-driven applications. Sadly, those patterns constitute a well-known source of design problems. The Reactive Programming (RP) paradigm has arisen as an approach to mitigate these problems. Yet, little evidence has been provided regarding the advantages of RP, and concerns have also arisen about the API usability of RP libraries given their disparate number of operators. In this work, we conduct a study on GitHub (GH) and Stack Overflow (SO) and explore three Reactive Extensions (Rx) libraries (RxJava, RxJS, and RxSwift) with the most GH projects to understand how much the vast Rx operators are being used. Also, we examine Rx SO posts to complement the results from the GH exploration by understanding the problems faced by RP developers and how they relate with the operators' frequencies found in open source projects. Results reveal that, in spite of its API size, the great majority of the Rx operators are actually being used (95.2%), with only a few, mostly related to RxJava, not being utilized. Also, we unveil 23 topics from SO with more posts concerning the Stream Abstraction (36.4%). Posts related to Dependency Management, Introductory Questions, and iOS Development figure as relevant topics to the community. The findings herein present can not only stimulate advancements in the field by understanding the usage of RP API and the main problems faced by developers, but also help newcomers in identifying the most important operators and the areas that are the most likely to be relevant for a RP application.

Hackathons and similar time-bounded events have become a popular form of collaboration in various domains. They are commonly organized as in-person events during which teams engage in intense collaboration over a short period of time to complete a project that is of interest to them. Most research to date has thus consequently focused on studying how teams collaborate in a co-located setting, pointing towards the advantages of radical co-location. The global pandemic of 2020, however, has led to many hackathons moving online, which challenges our current understanding of how they function. In this paper, we address this gap by presenting findings from a multiple-case study of 10 hackathon teams that participated in 4 hackathon events across two continents. By analyzing the collected data, we found that teams merged synchronous and asynchronous means of communication to maintain a common understanding of work progress as well as to maintain awareness of each other's tasks. Task division was self-assigned based on individual skills or interests, while leaders emerged from different strategies (e.g., participant experience, the responsibility of registering the team in an event). Some of the affordances of in-person hackathons, such as the radical co-location of team members, could be partially reproduced in teams that kept open synchronous communication channels while working (i.e., shared audio territories), in a sort of "radical virtual co-location". However, others, such as interactions with other teams, easy access to mentors, and networking with other participants, decreased. In addition, the technical constraints of the different communication tools and platforms brought technical problems and were overwhelming to participants. Our work contributes to understanding the virtual collaboration of small teams in the context of online hackathons and how technologies and event structures proposed by organizers imply this collaboration.

This paper proposes an agile learning management method based on Scrum to support autonomous learning for students. In conjunction with the proposed method, a case study was carried out involving students from several undergraduate courses participating in a software development training program based on Challenge Based Learning. In this study, the Scrum framework was adapted to support students' learning with their Challenge team and mentor's support. Events, artifacts, and team profiles were added, adapted, and excluded to improve the stu-dent's autonomous learning management. The case study covered data collected through questionnaires, interviews, observations, and archival records as a source for analysis. The use of the method showed significant results in learning, the management of Learning Objectives (LOs), and the participants' use experience. Besides, the study brings opportunities for improvements to the method and hypotheses for future work.

Hackathons and game jams are informal venues to engage STEAM (Science, Technology, Engineering, Arts, and Math) students in practical learning and nurturing interdisciplinary competencies (e.g., programming, design, communication). They also offer rich opportunities for networking and boosting the employability of participants. However, due to the not very inclusive culture created around them, these events may become hostile places for women. The low participation of women in hackathons and game jams may result in a loss of opportunity for them to improve their skills or to find jobs. Little is known about the motivations and perceptions of women participating in hackathons and game jams. We aimed at understanding (1) what are the typical gender-related problems women face in hackathons and game jams and how the perspective of men differ in regards to that problem; (2) how women perceive their motivations and their experience when participating in such events; and (3) what deters some women from participating. In this paper, we surveyed 211 participants of 8 events of this nature targeting higher education students with multidisciplinary backgrounds: 2 game jams (one of them women-focused) and 6 hackathons (one of them women-focused). Additionally, we applied a survey to hear the voice of 47 women who never attended these events to understand their lack of motivation. Through qualitative and quantitative data analysis, we compared the perspectives of men and women who participated in the studied hackathons and game jams. The qualitative data allowed us to investigate different experiences of women who reported discomfort in these events. As contributions of this paper, based on the collected data, we report different perspectives that men and women have about gender issues in these events and highlight the typical sexist behavior (bropriating, mansplaining, etc) of men participating in hackathons and game jams. Results showed that learning is the main motivation for both men and women to join these events. We also map the common reasons for women not being motivated to participate in these types of gatherings. Finally, we propose recommendations so that hackathons and game jams can increase gender equality. Our experience suggests these events, if well planned and executed, may become drivers to change attitudes and stereotypes regarding women in computing. By lowering those barriers, women can be more engaged and stimulated so they can also take advantage of more opportunities for STEAM learning in such informal settings.

In 2020, due to the COVID-19 pandemic, educational activities had to be done remotely as a way to avoid the spread of the disease. Instead of shifting to an online learning model, it consisted of a transition to what was called Emergency Remote Teaching. This is a strategy to keep activities going on until it is safe again to return to the physical facilities of universities. This new setting became a challenge to both teachers and students. The lack of interaction and classroom socialization became obstacles for students to continue engaged.

The hackathon phenomenon has just completed twenty years. During this period, it shifted from an event where highly skilled developers searched for bugs or randomly created a software solution to an organised event for exploring a set of technologies, challenges or themes. When promoted by software companies, these events are called corporate hackathons and mainly seek to improve their business activities by getting new ideas, prototypes or even business plans. By involving third parties, corporate hackathons become an open innovation strategy used by companies to ultimately leverage platforms and build a community of users around them, as a mechanism to establish a software ecosystem. This paper results from our motivation to understand how corporate hackathons are organised in IT industry. To achieve this goal, we performed a systematic mapping study on corporate hackathons, focusing on their process (i.e. steps involved in before, during and after a hackathon) and their main characteristics (goals, participants, duration, location, and application domain). As main contribution, we reveal organisation patterns and provide recommendations for companies aiming to conduct hackathons.

Edge computing has enabled the usage of Complex Event Processing (CEP) closer to data sources, delivering on time response to critical applications. One of the challenges in this context is how to support this processing and keep an optimal resource usage (e.g., Memory, CPU). State-of-art solutions have suggested computational offloading techniques to distribute processing across the nodes and reach such optimization. Most of them take the offloading decision through predefined policies or adaptive solutions with the usage of machine learning algorithms. However, these techniques are not able to incrementally learn without any historical data or to adapt to changes on statistical data properties. This research aims to use online learning and concept drift detection on offloading decision to optimize resource usage and keep the learning model up-to-date. The feasibility of our approach was noticed through preliminary evaluations.

Background: Nowadays, there is a massive growth of data volume and speed in many types of systems. It introduces new needs for infrastructure and applications that have to handle streams of data with low latency and high throughput. Testing applications that process such data streams has become a significant challenge for engineers. Companies are adopting different approaches to dealing with this issue. Some have developed their own solutions for testing, while others have adopted a combination of existing testing techniques. There is no consensus about how or in which contexts such solutions can be implemented. Aims: To the best of our knowledge, there is no consolidated literature on that topic. The present paper is an attempt to fill this gap by conducting an exploratory study with practitioners. Method: We used qualitative methods in this research, in particular interviews and survey. We interviewed 12 professionals who work in projects related to data streams, and also administered a questionnaire with other 105 professionals. The interviews went through a transcription and coding process, and the questionnaires were analysed to reinforce findings. Results: This study presents current practices around software testing in data stream processing applications. These practices involve methodologies, techniques, and tools. Conclusions: Our main contribution is a compendium of alternatives for many of the challenges that arise when testing streaming applications from a state-of-the-practice perspective.

Some researchers are starting to point out the importance of hackathons as an alternative venue for college students practicing and learning. Many positive aspects were highlighted such as peer learning and improvements in problem-solving, project management and task priority analysis. However, this hackathon phenomena is something that is happening outside the curriculum, with scarce reports of teachers taking advantage of similar approaches in undergraduate courses. In this article, we present our experience of an undergraduate introductory course on Distributed Systems where students have to participate in a "hack day" at the end of the semester. The goal is to take advantage of the hackathon model to bring a more realistic and engaging scenario where students can develop their course project and put into practice what they have learned in the semester. With this model, they have to do face-to-face group work and also have the opportunity to share knowledge with other groups. Our experience indicates positive results with this approach. Students reported a high level of engagement and enthusiasm. There were different situations of peer learning being reported, and according to their perception, students felt they learned more in the hack day than in lectures or laboratory practice.

Test cases are a set of test inputs, execution conditions, and expected results developed for a particular objective, such as to exercise a particular program path or to verify compliance with a specific requirement. Test cases that are written by students typically have recurring errors that make difficult to find hidden bugs or lack essential details about the data to be used and the instructions that must be followed. As an attempt to improve the quality of students test cases, we used a "Peanut butter and jelly sandwich challenge", typically used to teach algorithmic thinking, to show students the difficulties one may have repeating a simple set of instructions when they are not precisely described. That activity was adapted to cover contents focused on test case writing.

This paper describes a set of practices, techniques and conceptual tools that were tailored by combining ideas from Challenge-based Learning, Design Thinking and Lean Startup. While the former focuses on intrinsically motivating the students to engage in the learning process by tackling real-world problems aligned with their sense of purpose, the latter emphasizes aspects of the system being built, such as feasibility, viability, and desirability. The framework conception is as an innovative approach for mobile application development in long-term courses (1- or 2-year) involving programming, design, and business. We applied the methodology in the context of a regular undergraduate course including students with a diverse computing and non-computing backgrounds and collected their feedback during the process.

In this innovative practice full paper we present a methodology for organizing a hackathon as a learning instrument within the scope of an undergraduate course. Hackathons are short events (1 to 3 days), where participants motivated by a common challenge gather into groups to build a software or hardware prototype. Studies show that learning is one of the main motivators of hackathon participants. Researchers are also pointing out the importance of hackathons as an informal learning approach for college students. The acquisition of knowledge comes as a result of the practice itself and with participants learning from one another. This motivated us to bring that practice to the classroom, by offering an undergraduate course where students develop their semester project within a hackathon. In an attempt to systematize the steps, compress and optimize the time allocated for the ideation phase of hackathon projects, we propose a methodology for hackathons in an educational setting. The approach combines concepts from Challenge-based Learning and Design Thinking in a sequence of activities that streamlines the ideation process with regular deliveries in short time frames. This results in objective discussions and quick decision taking, fastly arriving at a project idea where students apply what they learned over the semester. We applied our approach in an Internet of Things undergraduate course within the scope of a semester project developed in an authentic 24-hour hackathon that took place in a maker space. This article details the methodology and presents a mixed methods study to analyze the students' perception on using this set of practices and techniques.

Hackathons are short-lived events, typically lasting from 1 to 3 days, where participants gather into groups to tackle a challenge and present a proof of concept in the form of software or hardware prototype, motivated by a common theme. Studies show that learning is one of the primary motivations for people joining hackathons, where situated and collaborative learning take place. The acquisition of knowledge comes as a result of the practice itself and with participants learning from one another. By taking that into account, we considered bringing hackathons into the classroom. This paper presents a case study of an Internet of Things (IoT) undergraduate course where a hackathon is used as a learning instrument, leveraging on challenge-based learning to motivate students to find and develop a suitable semester project. We utilize a mixed-method approach where quantitative and qualitative data are used to analyze the perspective of students about the effectiveness of that approach.

The concept of an “Internet of Things” (IoT) initially referred to a network where objects would be individually and instantly identified with Radio-Frequency Identification (RFID). Such concept was later evolved to a wider notion of heterogeneous objects using ubiquitous technologies to interact among them and with the physical environment. Among these technologies, Bluetooth, ZigBee, GPRS, NFC, QR code, can be cited some of those that were labeled as IoT technologies. Based on the possibility of linking ordinary objects from the physical world to the Internet, this paper proposes and details a platform called TagHunt, for creating and playing scavenger hunt games. It allows smartphones to interact with ordinary objects using IoT-based technologies such as NFC and QR Code, stimulating the user/player to interact with the surrounding environment looking for “clues” in the game. We performed an experiment involving four different scavenger hunt game scenarios created with the platform were we could evaluate user/player engagement when playing such games.

The concept of an “Internet of Things” (IoT) initially referred to a network where objects would be individually and instantly identified with Radio-Frequency Identification (RFID). Such concept was later evolved to a wider notion of heterogeneous objects using ubiquitous technologies to interact among them and with the physical environment. Among these technologies, Bluetooth, ZigBee, GPRS, NFC, QR code, can be cited some of those that were labeled as IoT technologies. Based on the possibility of linking ordinary objects from the physical world to the Internet, this paper proposes and details a platform called TagHunt, for creating and playing scavenger hunt games. It allows smartphones to interact with ordinary objects using IoT-based technologies such as NFC and QR Code, stimulating the user/player to interact with the surrounding environment looking for “clues” in the game. We performed an experiment involving four different scavenger hunt game scenarios created with the platform were we could evaluate user/player engagement when playing such games.

I/O bound systems can significantly reduce theirtotal execution time by performing I/O operationsconcurrently. Despite this enormous potential, most systemsperform I/O operations sequentially. One of the reasons behindthis is that the most widespread mechanisms for concurrentI/O are callback-based, resulting in code hard to write andmaintain. In this context, we propose Afluentes, a Javaframework that allows asynchronous functions to be composedjust as easily as synchronous ones, facilitating the developmentof concurrent I/O intensive systems. We performed anexperimental evaluation whose results showed that Afluentesleads to significant performance gains over sequential I/O.Compared to callback-based approaches, Afluentes leads tosimilar performance gains, but with less programming effort.

Interactive television is a new field for applications developers. However, the applications deployment has to take into account broadcast network constraints. This demonstration shows the design of service-oriented platform for the deployment of modular and dynamic iTV applications. Our proposition named OSGiTV is validated by a prototype of iTV platform using the OSGi platform and DVB MHP standards.

Exhibit sites, such as museums and commercial conventions, do not usually allow or motivate visitor interaction with the exhibited items. In this work we present an architecture for providing an augmented experience for exhibits. In our concept, visitors can use wireless handheld devices to scan the identifiers (e.g. RFID tags, 2D barcodes) of exhibit items and receive information about them or trigger events in the surrounding environment. We present a generic middleware which is dynamic, extensible and configurable, and is capable of generating different responses to visitor interactions. Responses can consider the visitor's profile, the exhibit's or visitor's history, administrative preferences, and other information. They include sending events to the visitor's device or to devices surrounding the exhibit. The architecture hides development complexity and takes advantage of various technologies, integrating them into our middleware and our handset application. We also provide administration capabilities, such as reporting and exhibit configuration. Our concept has been implemented and validated in a museum scenario and uses multiple technologies for communication, unique exhibit identification, and software dynamicity and extensibility.