Abstract—Online discussion forums are one of the most ubiq-uitous kinds of resources for people who are learning computer programming. However, their user interface – a hierarchy of textual threads – has not changed much in the past four decades. We argue that generic forum interfaces are cumbersome for learning programming and that there is a need for a domain-specific visual discussion forum for programming. We support this argument with an empirical study of all 5,377 forum threads in Introduction to Computer Science and Programming Using Python, a popular edX MOOC. Specifically, we investigated how forum participants were hampered by its text-based format. Most notably, people often wanted to discuss questions about dynamic execution state – what happens “under the hood ” as