Evaluating a Visual Query Tracer and Builder for Learning Declarative Logic Programming

Nemo Explain Visualizer (nev) is an interactive visual query tracer and builder for Nemo, a powerful Datalog reasoner with extended features. Our tools were developed with and for expert users. However, considering the lack of resources to learn Datalog and similar declarative logic programming languages, we conducted a qualitative user study to assess how our tools might help students. The study, interviewing 14 participants with varying levels of involvement with the content of a university course on knowledge graphs, revealed a very positive assessment of our tools, which strengthens the value of visual explanation tools beyond their intended use.