Ease of Use and Maintenance: A Note on Software Design

Article excerpt

Increasingly powerful hardware has prompted commercial software developers to concentrate not on highly efficient code but instead on usability. With much modern software sharing the same look and feel, a commercial edge can only be gained by increased usability leading to improved productivity. In the commercial world, usability ratings by NSTL (National Software Testing Labs) and similar institutions can affect sales significantly, in the same way that a poor review might prematurely end a play's run in the theatre.

In the field of voice output communication aids (VOCAs), client usability and high productivity (in terms of speech output rates) have always been priorities. However, much of this usability has typically centred around users themselves and not the rehabilitation worker, or health care professional, who might participate in developing the range of materials and experiences (maintenance) offered by such an aid. In fact, even in Beukelman and Ansel's (1995) enumeration of research priorities in augmentative and alternative communication, no direct mention is made about ease of maintenance of VOCAs by those who have to structure the contents of these devices. As VOCAs take account of new technologies and become increasingly advanced, they may remain highly accessible to users, but increasingly complex for typical maintainers who have to develop material for them. For example, a DECTalk/symbol based aid might require the writing and maintenance of scripts. This process can be complex, tedious, and, in time-pressured service environments, counter-productive.

A simple analogy illustrates the point. At Christmas, a child may receive a toy which needs to be assembled by an adult. The child sees only the completed toy with which they are very happy, but does not appreciate the effort expended by the adult. If the toy were constructed from fewer parts which were less complex it could be constructed more rapidly. This would enable the adult to have a better understanding of the toy's workings in case they needed to fix it, to play with the child for longer, and to reduce potential stress associated with the construction. In a similar way VOCA can be difficult to understand from a maintainer's prospective, which may mean that maintenance times are increased and frustrations raised. Naive maintainers are likely to suffer most in this respect.

Concentration on usability, although highly desirable, can mean that maintainers may easily become disillusioned about a specific VOCA. Negative perceptions regarding VOCA maintenance are usually to the detriment of the user. On the other hand with good design a VOCA can be made to be rewarding and productive for both users and maintainers. If a device enables maintainers to build complex materials easily, and offers instant rewards, ultimately this is likely to be of benefit to the user.

With modern philosophies of software design such as object orientation, the maintenance of VOCA can be made simple and rewarding if the maintainer interface is correctly designed. It is suggested that maintainers' attitudes and abilities to use a given VOCA should be incorporated into the development cycle as is currently the case with users. With the employment of standard user interface questionnaires, such as the QUIS (Shneiderman, 1992), failings can be addressed and strengths consolidated during the development phase. In our own research, by following the principle that users and maintainers share the same good design needs, such concerns have been addressed in parallel. In this instance the needs of users and maintainers are considered of equal importance.

This ethos has produced a software based VOCA known as "Easy Speaker" which, from a user's perspective, seamlessly integrates photorealistic symbols, digitised speech, video clips, animation, MIDI music and the like. By making use of dynamic displays, the user can communicate vocally, in addition to using the device as a learning and recreational environment in its own right. …