What situational information would help developers when using a graphical code recommender?
We aim to understand what situational information diagramming tools should provide to aid developers.We conduct a diary study where eleven developers use a novel diagramming tool in their daily work.We also analyze the data from the study by using grounded theory.Our study identifies five situations for which developers expect to use diagramming tools.Requirements for diagramming tools are also elaborated with regard to these five situations. Developers spend a significant amount of time trying to understand code bases. To aid developers' comprehension of code, researchers have developed software visualization tools. However, the uses of these tools in situ have rarely been investigated. To make matters worse, as studies have revealed, developers seldom use diagramming tools, making such investigations a challenge. To determine the possible uses of such tools in real practice, we conduct a diary study in which eleven developers in real-world developments use a novel visualization tool (a graphical code recommender) for one month. In the study, we ask what information and features the visualization and diagramming tools should provide to aid developers' work according to their situations. The study reveals the situations in which developers would use such visualization and diagramming tools and also the concrete requirements for such tools that would make them useful.