Augmented Reality (AR) has been proved useful to guide operational tasks in professional domains by reducing the shift of attention between instructions and physical objects. Modern smartphones make it possible to use such techniques in everyday tasks, but raise new challenges for the usability of AR in this context: small screen, occlusion, operation "through a lens". We address these problems by adding real-time feedback to the AR overlay. We conducted a controlled experiment comparing AR with and without feedback, and with standard textual and graphical instructions. Results show significant benefits for mobile AR with feedback and reveals some problems with the other techniques.

We present Stacksplorer, a new tool to support source code navigation and comprehension. Stacksplorer computes the call graph of a given piece of code, visualizes relevant parts of it, and allows developers to interactively traverse it. This augments the traditional code editor by offering an additional layer of navigation. Stacksplorer is particularly useful to understand and edit unknown source code because branches of the call graph can be explored and backtracked easily. Visualizing the callers of a method reduces the risk of introducing unintended side effects. In a quantitative study, programmers using Stacksplorer performed three of four software maintenance tasks significantly faster and with higher success rates, and Stacksplorer received a System Usability Scale rating of 85.4 from participants.