The effects of graphical and textual visualisations in a multi-representational debugging environment were investigated in computing students who used a software debugging environment (SDE) that allowed them to view the execution of programs in steps and that provided them with concurrently displayed, adjacent, multiple and linked representations. The experimental results are in agreement with research in the area that suggests that good debugging performance is associated with a balanced use of the available representations. Additionally, these results raise the issue of whether graphical visualisations promote a more judicious representation use than textual ones for program debugging in multi-representational environments.