IEEE VISSOFT is the most important conference in the field of software visualization. The 6th edition of the VISSOFT working conference took place in Madrid from 18-19 September 2018. We, David Baum and Leonel Merino, were happy to attend VISSOFT again this year. The two-day program contained two keynotes, ten presentations of full technical papers and six presentations about new ideas and emerging results as well as tool demos – and many interesting discussions around them.
This year Helen Purchase opened VISSOFT with her keynote speech on “Experimental Pitfalls”. In an instructive and entertaining lecture she spoke openly about mistakes made in empirical evaluations of information visualizations – and how to avoid them. With her more than 20 years of experiences in empirical evaluations she had a lot of stories to tell, e.g., that user studies are often mentioned in the Future Work section, but are rarely done once the paper is published. Helen showed several examples, in which the future work was carried out and led to surprising results. She shared some tips from her vast experience conducting evaluations, for instance, that evaluations are hard to design and conduct, and that they can always be improved. She also mentioned that usually experiments using within-subjects design lead to more insightful analysis than the more “clean” experiments that use a between-groups design. The take home message of her presentation was: Do user studies and do future work!
Helen Purchase about empirical evaluations in Future Work
Continuing a consistently incremental trend on the use of multiple media to display software visualizations, the topic of the first session was AR, VR, and 3D. Besides our presentations about adopting the city visualization for augmented reality  and using the visualization framework Getaviz for visualizing design erosion and architecture quality , Martin Misiak from DLR presented IslandViz  with a stunning presentation which was held almost completely in immersive virtual reality.
Many presentations focused on the tools that have been developed. For example,  RepoVis that improves the exploration of software repositories through full-text search and visualising of the search results and  an open source stack to unify heterogenous software artifacts in a graph database as a foundation for software analysis and software visualization. In contrary, Eduardo Faccin Vernier presented a more theoretical paper about dynamic treemap algorithms. He presented the evaluation of 12 well-known algorithms for different use-cases in the context of software evolution visualization with respect to different quality metrics.
Martin Misiak presentign IslandViz in VR and giving informal demo session afterwards.
The second day began with a keynote as well. This time, Aaron Quigley spoke about immersion. He made clear, that immersion does not depend on 3D visualization or virtual reality, but that the “flow state” can be achieved in many ways and for many tasks.
The final sessions focused on quality & architecture and program understanding. Two papers,  and , focused on the visualization of a multitude of metrics for providing a visual overview over big software systems. Ivan Bacher presented two NIER papers,  and . He presented an extended minimap visualization as used by many text editors by enriching it with more structural information and highlighting.
The Most Influential Paper (MIP) award was given to Steven Reiss for his paper “The Paradox of Software Visualization”  from 2005. The paper deals with the low usage of software visualization in industry although software visualization seems helpful and logical and many empirical evaluations show, how useful it is. In his lecture, which he gave remotely, Steve made clear, that the problems of software visualization from 2005 are unsolved and still apply 2018. Nevertheless he had to admit that software visualization have been adopted in some cases and that the situation might have been improved over the last decade.
One of the last events of the conference was the presentation of the best paper award. However, the program committee decided to not award a best paper, but instead two papers were given a distinguished paper award. First, the paper “Quantitative Comparison of Dynamic Treemaps for Software Evolution Visualization”  from Eduardo Faccin Vernier, Alexandru C. Telea and Joao Comba for their fundamental work on visualization techniques. Second, the paper “Overcoming Issues of 3D Software Visualization through Immersive Augmented Reality”  from Leonel Merino, Alexandre Bergel and Oscar Nierstrasz for their comprehensive and well conducted evaluation.
The winners of the distinguished paper award, Eduardo Faccin Vernier (left) and Leonel Merino (right), presented by Mircea Lungu and Andreas Kerren.
All in all, we had a great time at the conference attending the talks and meeting new people. The keynotes were definitely an enrichment for the conference and gave new impulses.
We both look forward to attend the next version of the conference Cleveland, USA. The conference website is already online, check it out: http://vissoft19.dcc.uchile.cl/
David Baum & Leonel Merino
David Baum (@naraesk)
PhD student at Leipzig University
Research group “Visual Software Analytics”
Leonel Merino (PhD)
Visualization Research Center (VISUS)
University of Stuttgart
 “Overcoming Issues of 3D Software Visualization through Immersive Augmented Reality. Leonel Merino, Alexandre Bergel and Oscar Nierstrasz.
 “Visualising Design Erosion: How Big Balls of Mud are Made”. David Baum, Jens Dietrich, Craig Anslow and Richard Müller.
 “IslandViz: A Tool for Visualizing Modular Software Systems in Virtual Reality” Martin Misiak, Andreas Schreiber, Arnulph Fuhrmann, Sascha Zur, Doreen Seider and Lisa Nafeie
 “RepoVis: Visual Overview and Full-Text Search in Software Repositories”. Johannes Feiner and Keith Andrews.
 “Towards an Open Source Stack to Create a Unified Data Source for Software Analysis and Visualization”. Richard Müller, Dirk Mahler, Michael Hunger, Jens Nerche and Markus Harrer.
 “Detecting Bad Smells in Software Systems with Linked Multivariate Visualizations”.
Haris Mumtaz, Fabian Beck and Daniel Weiskopf.
 “Quality Models Inside Out: Interactive Visualization of Software Metrics by Means of Joint Probabilities”. Maria Ulan, Sebastian Hönel, Rafael Messias Martins, Morgan Ericsson, Welf Löwe, Anna Wingkvist and Andreas Kerren.
 “The Code Mini-Map Visualisation: Encoding Conceptual Structures Within Source Code”. Ivan Bacher, Brian Mac Namee and John D. Kelleher.
 “Scoped: Evaluating A Composite Visualisation Of The Scope Chain Hierarchy Within Source Code”. Ivan Bacher, Brian Mac Namee and John D. Kelleher.
 “The Paradox of Software Visualization”. Steven P. Reiss
 “Quantitative Comparison of Dynamic Treemaps for Software Evolution Visualization”. Eduardo Faccin Vernier, Alexandru C. Telea and Joao Comba.