Runway incursions occur when an unauthorized aircraft, vehicle or pedestrian operates on a runway. While most incursions are near-misses, they have the potential of turning into fatal accidents such as the Tenerife accident. Despite various efforts to reduce runway incursions, the number of incursions has been increasing. Learning from past incidents can help us develop effective preventive strategies but lack of in-depth investigations limits our understanding of the causes of incursions. At towered airports, the controller on duty reports the incident to the FAA using a form asking them to describe the incident in their own words. Our research question is whether the current form contributes to the lack of detail in incident reports. To answer this question, we interviewed controllers and asked how they view incident reporting and the factors they consider while doing so. In this paper, we report the results of interviews with air traffic controllers.