This paper introduces a novel application called Graph Builder, which allows visually impaired people to interactively construct bar graphs using a force feedback device. We discuss the limitations of current technology to allow such interactive construction and explain why, in educational environments, such interactive construction is important. Evaluations of Graph Builder showed that users could construct graphs accurately. However results showed that a large number of ‘off-by-one’ errors occurred, where the bar was set either one unit too high or too low. Revisions to the mechanism to manipulate bars were made, and further non-speech audio feedback was added. A further evaluation showing that the proportion of ‘off-by-one’ errors had been reduced.