Conference

We present ViDI (Visual Design Inspector), a novel code review tool which focuses on quality concerns and design inspection as its cornerstones. It leverages visualization techniques to represent the reviewed software and augments the visualization with the results of quality analysis tools. To effectively understand the contribution of a reviewer in terms of the impact of her changes on the overall system quality, ViDI supports the recording and further inspection of reviewing sessions. ViDI is an advanced prototype which we will soon release to the Pharo open-source community.

During software development, exceptions are by no means exceptional: Programmers repeatedly try and test their code to ensure that it works as expected. While doing so, runtime exceptions are raised, pointing out various issues, such as inappropriate usage of an API, convoluted code, as well as defects. Such failures result in stack traces, lists composed of the sequence of method invocations that led to the interruption of the program. Stack traces are useful to debug source code, and if shared also enhance the quality of bug reports. However, they are handled manually and individually, while we argue that they can be leveraged automatically and collectively to enable what we call crowdstacking, the automated collection of stack traces on the scale of a whole development community. We present our crowdstacking approach, supported by Shore-Line Reporter, a tool which seamlessly collects stack traces during program development and execution and stores them on a central repository. We illustrate how thousands of stack traces stemming from the IDEs of several developers can be leveraged to identify common hot spots in the code that are involved in failures, using this knowledge to retrieve relevant and related bug reports and to provide an effective, instant context of the problem to the developer.

Understanding a problem domain is a fundamental prerequisite for good software design. In object-oriented systems design, modeling is the fundamental first phase that focuses on identifying core concepts and their relations. How to properly support modeling is still an open problem, and existing approaches and tools can be very different in nature. On the one hand, lightweight ones, such as pen & paper/whiteboard or CRC cards, are informal and support well the creative aspects of modeling, but produce artifacts that are difficult to store, process and reuse as documentation. On the other hand, more constrained and semi-formal ones, like UML, produce storable and processable structured artifacts with defined semantics, but this comes at the expense of creativity. We believe there exists a middle ground to investigate that maximizes the good of both worlds, that is, by supporting software modeling closer to its essence, with minimal constraints on the developer's creativity and still producing reusable structured artifacts. We also claim that modeling can be best treated by using the emerging technology of touch-based tablets. We present a novel gesture-based modeling approach based on a minimal set of constructs, and CEL, an iPad application, for rapidly creating, manipulating, and storing language agnostic object-oriented software models, which can be exported as skeleton source code in any language of choice. We assess our approach through a controlled qualitative study.

Modern software development sees code review as a crucial part of the process, because not only does it facilitate the sharing of knowledge about the system at hand, but it may also lead to the early detection of defects, ultimately improving the quality of the produced software. Although supported by numerous approaches and tools, code review is still in its infancy, and indeed researchers have pointed out a number of shortcomings in the state of the art. We present a critical analysis of the state of the art of code review tools and techniques, extracting a set of desired features that code review tools should possess. We then present our vision and initial implementation of a novel code review approach named Visual Design Inspection (ViDI), illustrated through a set of usage scenarios. ViDI is based on a combination of visualization techniques, design heuristics, and static code analysis techniques.

Most software engineering research focuses its analyses on source code, because correct, well designed, and efficient program code is the desired end output of software development. Nevertheless, source code is not the only constituent of software systems: Programs also comprise other types of artifacts, such as documentation, build system and configuration files, and graphics. These non-code artifacts only recently got the attention of researchers and are not yet investigated as a whole, but separately and with very specific aims. By taking a quantitative perspective, we look into non-code software artifacts to measure their role in software systems. We analyze 35 mature open-source software systems and we address exploratory questions such as: How many non-code software artifacts do software systems contain? How do they relate to source code? How much effort is put into producing and maintaining them? Our results show that a significant portion of systems is made of non-code artifacts, and that programmers spend a relevant part of their effort on non-code artifacts during the development process. Our analysis opens questions for future investigations.

It is common knowledge that program comprehension takes up a substantial part of software development. This \"urban legend" is based on work that dates back decades, which throws up the question whether the advances in software development tools, techniques, and methodologies that have emerged since then may invalidate or confirm the claim. We present an empirical investigation which goal is to confirm or reject the claim, based on interaction data which captures the user interface activities of developers. We use interaction data to empirically quantify the distribution of different developer activities during software development: In particular, we focus on estimating the role of program comprehension. In addition, we investigate if and how different developers and session types influence the duration of such activities. We analyze interaction data from two different contexts: One comes from the ECLIPSE IDE on Java source code development, while the other comes from the PHARO IDE on Smalltalk source code development. We found evidence that code navigation and editing occupies only a small fraction of the time of developers, while the vast majority of the time is spent on reading & understanding source code. In essence, the importance of program comprehension was significantly underestimated by previous research.

Technical questions and answers (Q&A) services have become a valuable resource for developers. A prominent example of technical Q&A website is StackOverflow (SO), which relies on a growing community of more than two millions of users who actively contribute by asking questions and providing answers. To maintain the value of this resource, poor quality questions - among the more than 6,000 asked daily - have to be filtered out. Currently, poor quality questions are manually identified and reviewed by selected users in SO, this costs considerable time and effort. Automating the process would save time and unload the review queue, improving the efficiency of SO as a resource for developers. We present an approach to automate the classification of questions according to their quality. We present an empirical study that investigates how to model and predict the quality of a question by considering as features both the contents of a post (e.g., from simple textual features to more complex readability metrics) and community-related aspects (e.g., popularity of a user in the community). Our findings show that there is indeed the possibility of at least a partial automation of the costly SO review process.

Integrated Development Environments (IDEs) have become the de facto standard vehicle to develop software systems. The user interface (UI) of an IDE offers a staggering amount of facilities to manipulate source code, such as inspectors, debuggers, recommenders, alternative viewers, etc. It is unclear how developers use the UI of an IDE and whether such UIs actually give appropriate support to the developers. We present a visual approach to understand and characterize development sessions from the UI perspective. The tool supporting our approach mines and processes the finest-grained UI-level events making up development sessions and presents them visually. We have collected, visualized, and analyzed hundreds of development sessions and report on our findings.