2.4 Usability of Telecommunications

Equipment and Services

Norman Gleiss, Jan Håvard Skjetne, Simon Richardson, Jan Heim


In the past, the characteristics of many services and their associated equipment, especially those intended for mass markets, have assumed that all users share a number of common psychological and physical attributes to the same extent. This has led to some potential users, especially those with some form of cognitive or physical limitation, to being alienated from many services that could facilitate social integration, improve the quality of life or support independent living. Thus, a two tier society emerges - those who have access to and can use technology, against those who have no access and cannot use it. For these reasons, and others related to the growing recognition that there is a large, but as yet only partially catered for market of disabled and elderly people, there has been a recent and significant change in some areas in the way new technologies and services are being designed. For example, in the European Union 4th Framework pro-gramme there is considerably more emphasis on disabled and elderly users than previously which is largely due to the recognition given in the so called "Bangemann Report" (Bangemann, 1994). A further example is the substantial effort made by Microsoft with Windows 95 0S to incorporate the requirements of this user group.

At the root of these initiatives is the concept of usability which can be expressed in the question:

"How can services and equipment be made more easy to use and easy to learn for a market of users who are not all the same and have different needs, capacities and characteristics ?"

What is Usability ?

Whilst it would be valuable to have a universal definition of the usability concept and its components, many different definitions are to be found in literature, some of which are language specific and cannot be easily translated into other languages. However, the actual terms are less important than what they stand for, so a clear description of the concepts is decisive. In any case, usability definitions need to be operational, i.e. what they mean depends on how they are measured (see for example, Shackle, (1992)).

Internationally, similar although not identical defini-tions are found in documentation from both ISO (International Organization for Standardization) and ETSI (European Telecommunications Standards Institute). The ISO Draft International Standard (DIS) 9241-11 "Guidance on usability specification and measures" define usability in the following way:

In its current standardization work, ETSI TC-HF (Human Factors Committee) and STC-HF3 (Usability Evaluation Subcommittee) have as far as possible made their definitions consistent with the forthcoming ISO standard. However, ETSI enhances the definitions by introducing the concept of utility.

1. Usability is considered as a purely ergonomic concept that does not depend on the cost of providing the systems. Instead, usability and financial costs form together the concept of Utility. This means that an ergonomically highly usable system may have low utility for a particular user who considers the cost to be too high in relation to his need for using the system.

One advantage of making a distinction between usability and utility is that the actual user (sometimes called the "end user") may not be concerned about costs if he is offered the equipment or service by the health and social care centre, but he still may be sensitive to the ergonomic usability which affects his work situation and performance. On the other hand the service provider, as the paying customer of the network operator, has to consider the utility by some sort of cost/benefit analysis, where usability is on the benefit side.

2. Measures of usability are assumed to be of two kinds:

a. Performance measures, which are "objective" measures or observations of user behaviour and are focused on the task performance, i.e. on how well the users can achieve a specific task. Performance measures include both effectiveness and efficiency.

b. Attitude measures, which are "subjective" measures of the users' opinions of working with the systems, i.e. how much they like to use the system. Attitude measures include terms such as satisfaction, acceptability and comfort.

How to Achieve Usable Products for Disabled and Elderly People

The development of a system can be thought as consisting of four different phases: specification, mock-up and early prototype, prototype and final product. The process should be iterative.

The importance of applying usability methods and tools throughout the development of new equipment and services cannot be overemphasized. Much effort and costs can be saved in the later stages of development if these principles are applied already in the specification phase. The cost of the changes later in the process is often 100 times greater than in the beginning. A general discussion of the issues of cost/benefit in relation to usability is given in (Shackel, 1992; Bias, 1994).

Elderly and disabled users should evidently be included in the user target group rather sooner than later. Guidelines and checklist data are rarely sufficient for completing a specification. Consequently, users should be involved already in the specification phase. Data collecting methods with users involved will be required in an early phase to produce the necessary information for a precise specification of the man/machine interface and of other characteristics of a service.

In the implementation phase using mock-ups and prototypes, usability testing is a natural part of the process. Various solutions for implementation in the terminal equipment or in the access procedures for a service may be tested and compared with each other, until an optimum solution is found.

In the last phase of the development process the step over to field studies may need to be taken, in order to validate the resulting product or service under real usage conditions before they are eventually introduced for public use.

Use of such methods needs to be comprehensive and can be time-consuming, but the investment can be expected to yield a high return in the end.


Today there are not many methods that specifically consider the needs of the elderly and disabled people. This information has up to now mainly remained in the disability community, and not been disseminated out to the designers. An increased interest can now be seen to be focusing on the usability of the product for these user groups, and some work is now specifically directed to this. The project USER under the TIDE research programme is one example which has developed a handbook and a toolset - USERfit, which hopefully will meet some of the designers needs regarding information in this field.

Even with the best tools and methods available, it is not possible to make a product that can be used by all the users with different disabilities. There are always some users who have conflicting requirements. It is however possible to make systems with a high degree of usability also for elderly and disabled people, if these methods and tools are used carefully.

The different usability methods and tools can be grouped into two different types: the first type uses experts and collected knowledge as guidelines and standards (see chapter 3-1), and the second one is based on user-centred methods, where the involvement of the users is essential.

Guidelines, standards and experts could be of great help for the design team in the specification phase, to check the design during the process and as a guide to avoid the most serious problems. They should however never be used alone. Today there are some guidelines that are intended to assist developers in the design of systems to be used by elderly and disabled people. Some of these guidelines are listed in Table 2-3. Experts in the fields of the needs for the elderly and disabled people can be found in the rehabilitation organizations.

It is interesting to note that the so called "user-centred", methods all have in common some activity aimed at getting information for design or evaluation through some kind of interaction with potential or actual users.

These interactions can be summarized under these few headings:

Although there are a great number of different techniques for collecting and analysing data, one or more variants of the methods mentioned above will almost always be involved in user-centred design.

One of the challenges for improving usability for products for elderly and disabled people is to adapt these methods to the specific requirements of the user group. How should you for example conduct an interview with a sign user, if you are not a sign user yourself ? How to involve intellectually impaired people in a discussion group ? Can you send questionnaires to blind people ? And what about motivation ? Will, for example, a person that has just experienced a serious accident be likely to participate in a user trial ?

Summing Up

As a general rule it is reasonable to say that the costs of involving elderly and disabled users in the development work with usability is much higher than with the rest of the population. So it is tempting to carry out the assessments with too few participants. The problem with this is accentuated by the fact that the variability within a group of disabled persons often is much bigger than within a "random sample" of the normal population. This may lead to the conclusion that all products should be specially designed for the single individual. Even if this may work in many cases, it is an impossible strategy for developing products for a mass market.

There is no general rule for overcoming these problems, however, here are some points that need to be considered:

List of reference design guidelines

BRANDT, Å. (Ed.) (1995) Telephones for all, Nordic Design Guidelines (NNH/3/95), The Nordic Committee on Disability, Stockholm.

ETSI - ETR 029. Human Factors (HF); Access to telecommunication for people with special needs. Recommendation for improving and adapting telecommunication terminals and services for people with impairments.

ETSI - ETR 166. Evaluation of Telephones for People with Special Needs.

VANDERHEIDEN, G. C. , Vanderheiden K.R. (Ed.) (1992). Accessible design of consumer products. Guidelines for the design of consumer products to increase their accessibility to people with disability or who are ageing. Working draft 1.7, Trace R&D Center, Madison.

VANDERHEIDEN, G. C. (1992). Making software more accessible for people with disabilities. A white paper on the design of software application programs to increase their accessibility for people with disabilities. (Release, No 1.2), Trace R&D Center, Madison.

(Table 2-3) List of reference design guidelines that take special account of disabled and elderly peoples needs.


BIAS, R.G. and MAYHEW, D.J. (1994). Cost - Justifying Usability, Academic Press.

ETSI - ETR 095 Human Factors; Guide for usability evaluations of telecommunications systems and services.

SHACKEL, B. and RICHARDSON, S.J. (1992). Human Factors for Informatics Usability. Cambridge University Press; Cambridge, UK.