Leonel Merino

Towards Actionable Visualisation in Software Development

Although abundant studies have shown how visualisation can help software developers to perform their daily tasks, visualisation is still not a common practice since developers have little support for adopting a proper visualisation for their needs. In this paper we review the 346 papers published in SOFTVIS/VISSOFT venues and identify 65 design study papers that describe how visualisation is used to alleviate various difficulties in software development. We classify these studies into several problem domains that we collected from the research on software development community, and highlight the characteristics of each study. On the one hand, we support software developers to put visualisation in action by mapping existing techniques to particular needs in various problem domains. On the other hand, we help researchers in the field by exposing domains with little visualisation support. We found a disconnect between the problem domains on which visualisation have focused and the domains that get the most attention from practitioners.

CityVR: Gameful Software Visualization

Gamification of software engineering tasks improve developer engagement, but has been limited to mechanisms such as points and badges. We believe that a tool that provides developers an interface analogous to computer games can represent the gamification of software engineering tasks more effectively via software visualization. We introduce CityVR – an interactive software visualization tool that implements the city metaphor technique using virtual reality in an immersive 3D environment medium to boost developer engagement in software comprehension tasks. We evaluated our tool with a case study based on ArgoUML. We measured engagement in terms of feelings, interaction, and time perception. We report on how our design choices relate to developer engagement. We found that developers i) felt curious, immersed, in control, excited, and challenged, ii) spent considerable interaction time navigating and selecting elements, and iii) perceived that time passed faster than in reality, and therefore were willing to spend more time using the tool to solve software engineering tasks.https://youtu.be/R0C-HMAtgnk

On the Impact of the Medium in the Effectiveness of 3D Software Visualizations

Many visualizations have proven to be effective in supporting various software related tasks. Although multiple media can be used to display a visualization, the standard computer screen is used the most. We hypothesize that the medium has a role in their effectiveness. We investigate our hypotheses by conducting a controlled user experiment. In the experiment we focus on the 3D city visualization technique used for software comprehension tasks. We deploy 3D city visualizations across a standard computer screen (SCS), an immersive 3D environment (I3D), and a physical 3D printed model (P3D). We asked twenty-seven participants (whom we divided in three groups for each medium) to visualize software systems of various sizes, solve a set of uniform comprehension tasks, and complete a questionnaire. We measured the effectiveness of visualizations in terms of performance, recollection, and user experience. We found that even though developers using P3D required the least time to identify outliers, they perceived the least difficulty when visualizing systems based on SCS. Moreover, developers using I3D obtained the highest recollection.

Walls, Pillars and Beams: A 3D Decomposition of Quality Anomalies

Quality rules are used to capture important implementation and design decisions embedded in a software systems architecture. They can automatically analyze software and assign quality grades to its components. To provide a meaningful evaluation of quality, rules have to stay up-to-date with the continuously evolving system that they describe. However one would encounter unexpected anomalies during a historical overview because the notion of quality is always changing, while the qualitative evolution analysis requires it to remain constant. To understand the anomalies in a quality history of a real-world software system we use an immersive visualization that lays out the quality fluctuations in three dimensions based on two co-evolving properties: quality rules and source code. This helps us to identify and separate the impact caused by the changes of each property, and allows us to detect significant mistakes that happened during the development process.

CommunityExplorer: A Framework for Visualizing Collaboration Networks

Understanding the network of collaborations, identifying the key players, potential future collaborators, and trends in the field are very important to carry out a project successfully. In this paper, we present CommunityExplorer, a visualization framework that facilitates presenting, exploring, and understanding the network of collaborations at once. The framework performs data extraction, parsing, and modeling automatically. It is easy to adopt and utilizes a bigraph visualization that scales well.We demonstrate the advantage of CommunityExplorer to identify the collaboration of authors on 346 and 104 research papers published in SOTFVIS/VISSOFT and IWST communities respectively. We found that even though SOFTVIS/VISSOFT has more contributors, IWST exhibits more collaboration.We discovered that contributors in IWST are more resilient than those in SOFTVIS/VISSOFT, which are more volatile. Moreover, collaboration in IWST is concentrated in a single large group, while in SOFTVIS/VISSOFT it is spread among many tiny groups and a few medium-sized ones.

Explora: A visualisation tool for metric analysis of software corpora

When analysing software metrics, users find that visualisation tools lack support for (1) the detection of patterns within metrics; and (2) enabling analysis of software corpora. In this paper we present Explora, a visualisation tool designed for the simultaneous analysis of multiple metrics of systems in software corpora. Explora incorporates a novel lightweight visualisation technique called PolyGrid that promotes the detection of graphical patterns. We present an example where we analyse the relation of subtype polymorphism with inheritance and invocation in corpora of Smalltalk and Java systems and find that (1) subtype polymorphism is more likely to be found in large hierarchies; (2) as class hierarchies grow horizontally, they also do so vertically; and (3) in polymorphic hierarchies the length of the name of the classes is orthogonal to the cardinality of the call sites.

A systematic literature review of software visualization evaluation

Abstract Context: Software visualizations can help developers to analyze multiple aspects of complex software systems, but their effectiveness is often uncertain due to the lack of evaluation guidelines. Objective: We identify common problems in the evaluation of software visualizations with the goal of formulating guidelines to improve future evaluations. Method: We review the complete literature body of 387 full papers published in the SOFTVIS/VISSOFT conferences, and study 181 of those from which we could extract evaluation strategies, data collection methods, and other aspects of the evaluation. Results: Of the proposed software visualization approaches, 62 lack a strong evaluation. We argue that an effective software visualization should not only boost time and correctness but also recollection, usability, engagement, and other emotions. Conclusion: We call on researchers proposing new software visualizations to provide evidence of their effectiveness by conducting thorough (i) case studies for approaches that must be studied in situ, and when variables can be controlled, (ii) experiments with randomly selected participants of the target audience and real-world open source software systems to promote reproducibility and replicability. We present guidelines to increase the evidence of the effectiveness of software visualization approaches, thus improving their adoption rate.

Towards actionable visualization for software developers: Towards Actionable Visualization for Software Developers

Abundant studies have shown that visualization is advantageous for software developers, yet adopting visualization during software development is not a common practice due to the large effort involved in finding an appropriate visualization. Developers require support to facilitate that task. Among 368 papers in SOFTVIS/VISSOFT venues, we identify 86 design study papers about the application of visualization to relieve concerns in software development. We extract from these studies the task, need, audience, data source, representation, medium, and tool, and we characterize them according to the subject, process, and problem domain. On the one hand, we support software developers to put visualization in action by mapping existing visualization techniques to particular needs from different perspectives. On the other hand, we highlight the problem domains that are overlooked in the field and need more support.