Technology Category
Humans and AI: AI for AccessibilityComputer Vision: Language and VisionCognitive Modeling & Cognitive Systems: Adaptive Behavior
An Extension-Based Accessibility Framework for Making Blockly Accessible to Blind and Low-Vision Users
🤖 AI Summary
This work addresses the lack of accessibility in block-based programming environments like Blockly for blind and low-vision users, a challenge exacerbated by existing solutions that require intrusive modifications to the core codebase, hindering deployment. To overcome this, the authors propose an extensible accessibility framework (EAF) featuring a modular architecture that enables seamless integration without altering Blockly’s source code. The framework introduces a novel three-dimensional hierarchical navigation model, combining stack labels, block numbering, and mode-based editing, while adhering to WAI-ARIA standards for compatibility with mainstream screen readers such as VoiceOver, JAWS, and NVDA. Evaluation across 177 test cases on two Blockly platforms demonstrates its effectiveness, with user feedback indicating significant improvements over default keyboard navigation—particularly in spatial orientation and mental model construction.
Technology Category
Application Category
📝 Abstract
Block-based programming environments (BBPEs) such as Scratch and Code.org are now widely used in K-12 computer science classes, but they remain mostly inaccessible to blind or visually impaired (BVI) learners. A major problem is that prior accessibility solutions have relied on modifications to the Blockly library, making them difficult to apply in existing BBPEs and thereby limiting adoption. We present an Extension-based Accessibility Framework (EAF) to make BBPEs accessible for BVI students. The framework uses a modular architecture that enables seamless integration with existing Blockly-based BBPEs. We present an innovative three-dimensional (3D) hierarchical navigation model featuring stack labeling and block numbering, mode-based editing to prevent accidental modifications, and WAI-ARIA implementation to ensure compatibility with external screen readers. We evaluated our approach by integrating the EAF framework into two BBPEs (covering 177 test cases) and conducting semi-structured interviews with four participants using VoiceOver, JAWS, and NVDA. Participants reported clearer spatial orientation and easier mental model formation compared to default Blockly keyboard navigation. EAF shows that modular architecture can provide comprehensive accessibility while ensuring compatibility with existing BBPEs.
Problem
Research questions and friction points this paper is trying to address.
block-based programming environments
blind and low-vision users
accessibility
Blockly
screen reader compatibility
Innovation
Methods, ideas, or system contributions that make the work stand out.
Extension-based Accessibility Framework
3D hierarchical navigation
modular architecture
WAI-ARIA
block-based programming accessibility
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