Improving Understanding of Data Structures for the Blind with Tactile Media and a User-Centered Iterative Approach

This Innovative Practice Full Paper addresses the challenges of teaching data structures and algorithms to blind students using tactile media and a user-centered approach. Computer Science educators have have long used diagrams and other visualizations to assist in teaching data structures and algorithms. As enrollments in computer science rise, a more diverse student body has led to widespread access to computer science, including an increase in the number of students with sight impairments that are seeking computer science degrees. In the Department of Computer Science at Tennessee Technological University we have been actively engaging in the development of methodologies and approaches necessary to facilitate creation of tactile documents suitable for helping students with sight impairments to understand and effectively use common data structures. Using tools generally available to practitioners, we applied a user-centered iterative process to develop standards necessary to create visual idioms that capture various data structures and algorithms as diagrams expressed using tactile documents. With feedback from our visually impaired students, we created several diagrams that represent various data structures using common drawing tools such as Microsoft Visio with Braille font. These documents were then printed using swell paper and a tactile printer. Students using these diagrams have reported gaining an increased understanding of concepts that were previously static abstractions only read about in their textbooks. Many lessons have been learned along the way that range from the general (i.e., how to properly space words in order to not affect ambiguity in the layout of diagrams) to the specific (i.e., how to demonstrate movement of data in a data structure using the tactile medium). In this paper, we report on the approaches used to create tactile diagrams representing various data structures, the ways in which we interacted with students in order to gain a better understanding of how to represent visual idioms in tactile form, challenges faced in creating the documents, and lessons learned. In addition, we discuss the work in the context of the state of the art, and suggest future investigations.