Volume I Number 1, January 1994

Development of an Accessible User Interface for People who are Blind or Vision Impaired as Part of the Re-Computerisation of Royal Blind Society

Tim Noonan
Adaptive Technology Services Manager


As part of an upgrade of its online computer systems and applications, Royal Blind Society (RBS) has collaborated with Deen Systems (DS) in the development of a new user interface optimised for access by blind or vision impaired (BVI) people. The design and special features of this user interface are the main focus of this article. "User interface" refers to those aspects of a computer program which display information to the user and which interpret and/or elicit input (i.e., commands to be issued from the keyboard) from the user. Because the user interface described below is intended for use by vision impaired people, it is referred to here as the VI interface to distinguish it from the regular interface. Three main groups of business applications will ultimately be available in this integrated environment: marketing and fund raising system, client tracking and service delivery statistics system and, finally, a system to track and coordinate the production of alternative format materials and to handle circulation and cataloguing of library materials.

Screen reading programs for MS-DOS are all tailored to provide access to DOS applications. When developing an application on a remote computer using a terminal program to access that application, the remote application has no way of taking advantage of hardware aspects of the PC as PC-based programs sometimes do. For example, DOS programs can send material to the screen in two ways: one which will speak, one which will not. Programs on a PC can use scrolling text, highlighting and reliable use of cursor keys and remain compatible with most modern adaptive technology. Remote applications can cause major compatibility problems with adaptive technology when they employ similar facilities; this article describes our experiences with and solutions to the issue of compatibility.

Objectives of the Development

Following a major review of RBS's information technology requirements in 1990, Deen Systems, as part of a consortium, successfully tendered to undertake the development of RBS's new business systems. Deen Systems was responsible for the database design and programming of the online systems but RBS worked very closely with Deen Systems in the development of an accessible VI interface. We began with a list of basic screen design principles (see below) and jointly came up with solutions to material which was more involved than the basic principles could deal with.

Adherence to the following principles was fundamental to ensuring that Deen Systems and RBS did not lose sight of the basic requirements for consistency and minimal differences between the regular and VI interfaces. Our guiding principles included:

Hardware and Software Environment

Our new online systems are being developed in a UNIX environment. UNIX is text-oriented, making it compatible with major adaptive hardware and software products by use of terminal emulation software on a PC. UNIX also provides machine-readable documentation which is accessible to all users, as well as a variety of text processing utilities. UNIX is in a good position to become the preferred text environment for BVI people in the 90s as DOS becomes displaced and outdated by the continuing move towards graphical user interfaces and multi-tasking.

All of our online users have access to an MS-DOS PC to access the Unix computer. For BVI users, this PC is equipped with speech, braille or large print technology to enable access to programs on the PC as well as the UNIX applications. We find that MS-DOS Kermit version 3.12 works ideally with adaptive technology devices. While most PCs are equipped with Ethernet connections to the UNIX machine, serial and modem connections are also in use and work well with the VI interface.

Our applications are based on the INGRES Relational Database Management System (RDBMS). Because we will have three or more applications, each sharing much common data (e.g., names and addresses), an integrated relational data base which is managed independently allows us to minimise duplication of data, ensure data integrity, and provide very flexible reporting.

The applications are written in a fourth generation language called Ochre. Fourth Generation Languages are now commonly used for the design of business and database applications. 4GLs aim to minimise the time spent writing lines of code for common tasks thus leaving the programmer time to concentrate on the "what" that the program is supposed to do, and the 4GL deals with the "how" of low level programming. 4GLs allow a more humanly readable program to be written and then convert this into thousands of lines of low-level code which is executed by the database management system behind the scenes. Advantages of Ochre include:

Guiding Principles of the User Interface Development

Some of these principles were set out before development of the user interface, others were recognised as we moved further into the development process.

Screen Design Issues

Screen layouts and field ordering must all be well-defined. A limited set of "standard" screen layouts were defined for sighted and VI interfaces. Except in rare special circumstances, such screen standards are used. Some of the screen design principles we follow are:


We began the planning and development of this system at the start of 1991. We now have our marketing and fund raising systems completed and they are being used extensively by sighted and BVI staff. Although it is recognised that there are further enhancements which could be made to the user interface, the objectives of easy and efficient access to the systems by all users have been achieved.

Working with Deen Systems provided a unique opportunity; as developer of both the programming language (Ochre) and our online applications, Deen Systems' programmers brought an in-depth understanding of all levels of design to each stage of the development process. This collaboration has benefitted both RBS and DS. RBS has greatly enhanced the ease and efficiency of access to its systems by both sighted and BVI users; Deen Systems came away with a superior product and greater understanding of the needs of computer users with disabilities.

Tim Noonan is Adaptive Technology Services Manager at Royal Blind Society. He heads a multi-disciplinary team responsible for providing such services as adaptive technology assessment, training vision impaired people in the use of computers, and the dissemination of product information. Tim is also responsible for the development of systems to improve alternative format production processes and to generally improve the accessibility of RBS positions and activities.

Royal Blind Society
4 Mitchell Street
Enfield NSW 2136 Australia
Phone: +612 334 3333
Fax: +612 747 5993
Email: Tim Noonan
Noonan, T. (1994). Development of an accessible user interface for people who are blind or vision impaired as part of the re-computerisation of Royal Blind Society. Information Technology and Disabilities E-Journal, 1(1).