Accessible Blockly: An Accessible Block-Based Programming Library for People with Visual Impairments

The visual and mouse-centric nature of block-based programming environments generally make them inaccessible and challenging to use by users with visual impairments who rely on assistive technologies to interact with computers. This prevents these users from participating in programming activities where these systems are used. This paper presents a prototype of an accessible block-based programming library called Accessible Blockly that allows users to create and navigate block-based code using a screen reader and a keyboard. This is an attempt to make the famous Blockly library accessible through a screen reader and keyboard. In this paper, we present the design and implementation of Accessible Blockly. We also discuss the evaluation of the library for block-based code navigation in a study with 12 blind programmers. Analysis of the study results shows that Accessible Blockly effectively aids users with reading and understanding block-based code. Participants found Accessible Blockly easy to use and less frustrating for navigating block-based programs. The participants also expressed enthusiasm and interest in using the keyboard and screen reader to navigate block-based code and in the accessibility of block-based programming.