Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Computer-based virtual worlds are increasingly used for activities which previously required physical environments. However, in its mainstream form, such a virtual world provides output on a graphical display and is thus inaccessible to a blind user. To achieve accessibility for blind users, an alternative to graphical output must be used. Audio and text are two output methods that can be considered. However, when using audio, care must be taken not to overload the audio channel. Channel overloading is possible with audio since it is not a selective output medium like the visual channel, that is, the user cannot choose what he/she wants to hear. Text should also be treated as audio, since a blind user consumes textual information as synthesized speech. In this research we discuss one possible solution to the problem of channel overloading, by the use of multiple exploration and navigation tools. These tools should allow the user to shape the information provided as audio output. Specially, we discuss the development of a virtual world client called Perspective, enabling non-visual access to virtual worlds by the use of multiple navigation and exploration tools. Perspective also serves as a framework for tool implementation and evaluation. Finally we give recommendations for improvements to current virtual world building practices and protocols, as to work toward an accessibility standard. / AFRIKAANSE OPSOMMING: Rekenaargebaseerde virtuele wêrelde word toenemend gebruik vir aktiwiteite wat voorheen fiesiese omgewings benodig het. Tog verskaf so 'n virtuele wêreld, in sy standaard vorm, afvoer as 'n grafiese beeld en is dus ontoeganklik vir 'n blinde gebruiker. Om toeganklikheid vir blinde gebruikers te bewerkstellig, moet 'n alternatief vir die grafiese beeld gebruik word. Klank en teks is twee alternatiewe wat beskou kan word. Tog moet klank versigtig gebruik word, aangesien die klankkanaal oorlaai kan word. Die klankkanaal kan oorlaai word aangesien dit nie 'n selektiewe kanaal soos die visuele kanaal is nie, met ander woorde, die gebruiker kan nie kies wat hy/sy wil hoor nie. Teks moet ook as klank beskou word, aangesien 'n blinde gebruiker teks in die vorm van gesintetiseerde spraak inneem. Met hierdie navorsing bespreek ons een oplossing vir die probleem van kanaaloorlading, deur die gebruik van verskeie navigasie- en verkenningsgereedskapstukke. Hierdie gereedskapstukke behoort die gebruiker in staat te stel om die inligting wat as klank oorgedra word, te bepaal. Ons bespreek spesi ek die ontwikkeling van 'n virtuele wêreld-kliënt genaamd Perspective, wat nie-visuele toegang tot virtuele wêrelde bewerkstellig deur die gebruik van meervoudige navigasie- en verkenningsgereedskapstukke. Perspective dien ook as 'n raamwerk vir die ontwikkeling en evaluering van gereedskapstukke. Laastens verskaf ons voorstelle vir verbeteringe van die boutegnieke en protokolle van huidige virtuele wêrelde, as eerste stap na 'n toeganklikheidsstandaard vir virtuele wêrelde.

Particularly in recent years, prompted by the need to gain greater independent access to a wider range of information, many persons who are blind make extensive use of screen access technology, optical character recognition devices, refreshable Braille displays and electronic notetakers in a variety of contexts. These reading and writing media have proved to be so useful and effective, raising debates in the literature on whether there is a decline in the use of Braille, or whether Braille as a reading and writing medium would become obsolete. Following a discussion on the development of tactual reading and writing media as part of an historical background to blindness, as well as an evaluation of the various reading and writing media used in South Africa by persons who are blind, this study, using a quantitative approach with a survey design, aimed to determine the impact of the various reading and writing media on the education and employment of persons who are blind. Based on the findings of the study, what emerges forcefully with regard to the preference of a medium for reading or writing is that a greater number of persons who are blind prefer Braille and computers with speech output. Notwithstanding this, there is support for the need to provide instruction in the use of the various reading and writing media, highlighting the critical value and role of the various media. Additionally, while persons who are blind appear to be convinced that computers will not replace Braille, they were, however, divided on whether there is a decline in the use of Braille, and whether computers would replace audiotapes. Finally, conclusions, based mainly on the findings of the study are drawn, and recommendations, both for future research, and for an integrated reading and writing model, are made. / Educational Studies / D.Ed.(Special Needs Educstion)

Particularly in recent years, prompted by the need to gain greater independent access to a wider range of information, many persons who are blind make extensive use of screen access technology, optical character recognition devices, refreshable Braille displays and electronic notetakers in a variety of contexts. These reading and writing media have proved to be so useful and effective, raising debates in the literature on whether there is a decline in the use of Braille, or whether Braille as a reading and writing medium would become obsolete. Following a discussion on the development of tactual reading and writing media as part of an historical background to blindness, as well as an evaluation of the various reading and writing media used in South Africa by persons who are blind, this study, using a quantitative approach with a survey design, aimed to determine the impact of the various reading and writing media on the education and employment of persons who are blind. Based on the findings of the study, what emerges forcefully with regard to the preference of a medium for reading or writing is that a greater number of persons who are blind prefer Braille and computers with speech output. Notwithstanding this, there is support for the need to provide instruction in the use of the various reading and writing media, highlighting the critical value and role of the various media. Additionally, while persons who are blind appear to be convinced that computers will not replace Braille, they were, however, divided on whether there is a decline in the use of Braille, and whether computers would replace audiotapes. Finally, conclusions, based mainly on the findings of the study are drawn, and recommendations, both for future research, and for an integrated reading and writing model, are made. / Educational Studies / D.Ed.(Special Needs Educstion)