Web-based teaching: communicating technical diagrams with the vision impaired

Technical diagrams are an inescapable part of professional life. In the IT (information technology) field, advancement often involves the ability to analyse and design systems, requiring the preparation and interpretation of diagrams. One standard vehicle for achieving this in the object-oriented community is with the Unified Modeling Language (UML). The UML is a visual communication tool which conveys non-visual (structural) information about program architecture. Where students have vision impairments, particularly blindness, alternative communication mechanisms need to be discovered that will enable such students to understand the concepts and develop into fully capable IT professionals. This paper contains a review of techniques and products that may enable blind programmers to 'read' UML diagrams.