Renato Lima Novais

Software evolution visualization: A systematic mapping study

Background: Software evolution is an important topic in software engineering. It generally deals with large amounts of data, as one must look at whole project histories as opposed to their current snapshot. Software visualization is the field of software engineering that aims to help people to understand software through the use of visual resources. It can be effectively used to analyze and understand the large amount of data produced during software evolution. Objective: This study investigates Software Evolution Visualization (SEV) approaches, collecting evidence about how SEV research is structured, synthesizing current evidence on the goals of the proposed approaches and identifying key challenges for its use in practice. Methods: A mapping study was conducted to analyze how the SEV area is structured. Selected primary studies were classified and analyzed with respect to nine research questions. Results: SEV has been used for many different purposes, especially for change comprehension, change prediction and contribution analysis. The analysis identified gaps in the studies with respect to their goals, strategies and approaches. It also pointed out to a widespread lack of empirical studies in the area. Conclusion: Researchers have proposed many SEV approaches during the past years, but some have failed to clearly state their goals, tie them back to concrete problems, or formally validate their usefulness. The identified gaps indicate that there still are many opportunities to be explored in the area.

Information visualization for emergency management

We report a mapping study to analyze visualization tools in emergency management.Map the area (scientific community and the contributions published in the literature).We point common visualization techniques, environments and phases.Existent literature provides only partial solutions.Findings can support on proposing new approaches to solve open problems in the area. Background: Emergency management (EM) refers to the ability to deal with emergency tasks in different phases and iterations. To do this, each task requires many and different types of information coming from several sources related to the incident. As people working in an emergency situation are generally under stress and have to make quick and effective decisions, they need to assimilate the received information in an easy and intuitive way. Information visualization (InfoVis) is the study of visual representations of abstract data to reinforce human cognition to understand these data through 2D computer screens. It is frequently used to analyze and understand the huge amount of multidimensional data produced in an emergency.Objective: This study analyzes how researchers use information visualization tools to improve emergency management. Our general objective is to map the area examining both the scientific community and the contributions that have been published in the literature, aiming to provide information, such as: understanding how the area is structured, common practices in existing works, and research gaps.Methods: A systematic mapping study was conducted to analyze the available information visualization tools and their applications in EM activities. A thorough search was carried out and a formal selection process was applied to gather all relevant articles on the subject. Selected primary studies were classified and analyzed with respect to their metadata and to answer eight research questions related to our mapping goal. In total, 196 studies were analyzed in depth.Results: The mapping study identified the most common visualization techniques applied in emergency management, the common environments and phases where they are applied, identifying gaps and also possible trends in the subject. We found out that particular issues concerning emergency management are not fully covered by existing visualization approaches, and when covered, existing literature provides only partial solutions.Conclusion: Our results provide a deep analysis on the application of InfoVis in the EM area, supporting researchers and developers in EM systems with insightful information on trending techniques in use, command practices and existing research gaps. We expect that these findings can support them on proposing new approaches to solve open problems in the area.

On the Use of Software Visualization to Analyze Software Evolution: An Interactive Differential Approach

Software evolution is one of the most important topics in modern software engineering research. This activity requires the analysis of large amounts of data describing the current software system structure as well as its previous history. Software visualization can be helpful in this scenario, as it can summarize this complex data into easy to interpret visual scenarios. This paper presents an interactive differential approach for visualizing software evolution. The approach builds multi-view structural descriptions of a software system directly from its source code, and uses colors to differentiate it from any other previous version. This differential approach is highly interactive allowing the user to quickly brush over many pairs of versions of the system. As a proof of concept, we used the approach to analyze eight versions of an open source system and found out it was useful to quickly identify hot spot and code smell candidates in them.

VisMinerTD - An Open Source Tool to Support the Monitoring of the Technical Debt Evolution using Software Visualization

Software development and maintenance activities can be negatively impacted by the presence of technical debt. One of its consequences is the software quality decrease. In order to produce better software, the evolution of technical debt needs to be monitored. However, this is not a trivial task since it usually requires the analysis of large amount of data and different types of debt. The areas of metrics and software visualization can be used to facilitate the monitoring of technical debt. This paper presents an open source tool called VisMinerTD that uses software metrics and visualization to support developers in software comprehension activities including the identification and monitoring of technical debt. VisMinerTD brings a new perspective to the hard work of identifying and monitoring technical debt evolution on software projects. Moreover, the user can easily plug new metrics and new visual metaphors to address specific technical debt identification and monitoring activities.

The problem of conceptualization in god class detection: agreement, strategies and decision drivers

BackgroundThe concept of code smells is widespread in Software Engineering. Despite the empirical studies addressing the topic, the set of context-dependent issues that impacts the human perception of what is a code smell has not been studied in depth. We call this the code smell conceptualization problem. To discuss the problem, empirical studies are necessary. In this work, we focused on conceptualization of god class. God class is a code smell characterized by classes that tend to centralize the intelligence of the system. It is one of the most studied smells in software engineering literature.MethodA controlled experiment that extends and builds upon a previous empirical study about how humans detect god classes, their decision drivers, and agreement rate. Our study delves into research questions of the previous study, adding visualization to the smell detection process, and analyzing strategies of detection.ResultOur findings show that agreement among participants is low, which corroborates previous studies. We show that this is mainly related to agreeing on what a god class is and which thresholds should be adopted, and not related to comprehension of the programs. The use of visualization did not improve the agreement among the participants. However, it did affect the choice of detection drivers.ConclusionThis study contributes to expand empirical evidences on the impact of human perception on detecting code smells. It shows that studies about the human role in smell detection are relevant and they should consider the conceptualization problem of code smells.

A systematic mapping study on mining software repositories

Background: Software repositories provide large amount of data encompassing software changes throughout its evolution. Those repositories can be effectively used to extract and analyze pertinent information and derive conclusions related to the software history or its current snapshot. Objective: This work aims to investigate recent studies on Mining Software Repositories (MSR) approaches collecting evidences about software analysis goals (purpose, focus, and object of analysis), data sources, evaluation methods, tools, and how the area is evolving. Method: A systematic mapping study was performed to identify and analyze research on mining software repositories by analyzing five editions of Working Conference on Mining Software Repositories -- the main conference on this area. Results: MSR approaches have been used for many different goals, mainly for comprehension of defects, analysis of the contribution and behavior of developers, and software evolution comprehension. Besides, some gaps were identified with respect to their goals, focus, and data source type (e.g. lack of usage of comments to identify smells, refactoring, and issues of software quality). Regarding the evaluation method, our analysis pointed out to an extensive usage of some types of empirical evaluation. Conclusion: Studies of the MSR have focused on different goals, however there are still many research opportunities to be explored and issues associated with MSR that should be considered.

An interactive differential and temporal approach to visually analyze software evolution

Software evolution is one of the most important topics in modern software engineering research. It deals with complex information and large amounts of data. Software visualization can be helpful in this scenario, helping to summarize, analyze and understand software evolution data. This paper presents SourceMiner Evolution (SME), a software tool that uses an interactive differential and temporal approach to visualize software evolution. The tool is implemented as an Eclipse plug-in and has four views that are assembled directly from the IDE AST. The views portray the software from different perspectives. One view shows how metrics of a chosen software entity evolves over time. The other three views show differential comparisons of any two versions of a system structure, dependency and inheritance properties.

Visualization mechanisms for crowdsourcing information in emergency coordination

To perform emergency coordination, people in a command centre need to process a large amount of data about the incident to make decisions, generally, under time pressure. A main challenge is to quickly obtain contextual information about the situation, which can be obtained from people in the place of the incident, in a crowdsourcing manner. This paper presents our investigation about visualization mechanisms to support command centres on analysing crowdsourcing information regarding emergency situations. As contributions, we highlight: 1) discussion of existing visualization mechanisms and their support on emergency management; 2) prototype of the Emergency Response Toolkit (ERTK), a set of tools to support command centres on using information from the crowd, e.g. in large-scale events; and 3) evaluation of ERTK and its visualization mechanisms with 11 emergency experts, in Brazil, Austria and Spain, collecting feedback to improve information visualization for emergency management.

Investigating the Relationship between Code Smell Agglomerations and Architectural Concerns: Similarities and Dissimilarities from Distributed, Service-Oriented, and Mobile Systems

Context: software architects often decide on strategies before incorporating an asset (e.g., components) in software systems. At the same time, they are responsible for preventing code and architectural degradation caused by design problems. Problem: groups of code smells (a.k.a. agglomeration of code smells) have been recognized as a source of design problems, but no previous study has analyzed the relationship between such agglomerations and different types of software. Different types of software have different needs in terms of implementation of architectural concerns, which can lead to consequential variations in the way how code smells agglomerate. Goal: this study aims to understand how a varied set of projects and their respective architectural concerns relates to code smells agglomerations. Method: our study analyses the history of 15 Open Source Software (OSS) projects split as three groups of distributed, service-oriented, and mobile project types. It mines the projects for code smells and architectural concerns (identified from injected components). It agglomerates instances of code smells around these concerns, and analyzes them according to the grouped projects. Results/Discussion: the agglomerations of smells tend to follow a stratified pattern in which they group themselves through ramifications of similarities and dissimilarities of concerns and project types.

Quality Attributes Analysis in a Crowdsourcing-based Emergency Management System.

In an emergency situation where the physical integrity of people is at risk, a mobile solution should be easy to use and trustworthy. In order to offer a good user experience and to improve the quality of the app, we should evaluate characteristics of usability, satisfaction, and freedom from risk. This paper presents an experiment whose objective is to evaluate quality attributes in a crowdsourcing-based emergency management system. The quality attributes evaluated are: appropriateness recognisability, user interface aesthetics, usefulness, trust, and health and safety risk mitigation. The experiment was designed following the Goal/Question/Metric approach. We could evaluate the app with experts from the area of emergency. The results showed that the participants thought the app was well designed, easy to understand, easy to learn, and easy to use. This evaluation ensured the application improvement, and also the evaluation process adopted.