Visual programming languages (VPLs) were designed to assist children in introductory programming courses. Unfortunately, despite the positive results in teaching, VPLs are believed to be inaccessible for children with visual impairments and low vision due to the dependency of visual graphics as both input and output methods. To identify the barriers that users with visual impairments and low vision face while using Block-based programming environments, as well as to acquire feedback regarding the design of a new tangible programming tool prototype, a usability study was conducted which involved nine adult participants with visual impairments and low vision. This paper presents the findings of this usability study and provides a list of features that are needed in order to make Block-based environments accessible. Furthermore, based on observations, interviews, and post-surveys this study demonstrates that our prototype can be used by users with visual impairments and low vision and provides a guideline for the design of tangible interfaces to teach programming concepts.
Accessibility of Block-Based Introductory Programming Languages and a Tangible Programming Tool Prototype