User-centred design
| El.pub News |
A free email alerter of the latest news items and associated URLs. |
User-centred design | Usability assessment | Design guide for multimedia | INUSE project | Download information pack
User-centred design methods can help you produce systems which are easy to use and match the real needs of your users.
The full benefits of user-centred design can be achieved by increasing the maturity of the systems development process until it reaches level 5 on the following scale:
- Usability is considered irrelevant: user interfaces are designed without expertise
- Usability is thought to be common-sense: a GUI is layered on afterwards
- Usability is carried out but is unfocused: the user interface is only tested for usability when too late to make many changes.
- Usability is integrated into development: human factors principles are applied to user interface design.
- Usability is integrated throughout the lifecycle: user-centred design methods are used to match the product to user needs.
Making systems more usable has substantial economic and social benefits. Difficult to use systems are more stressful for the user. The European Display Screens Directive puts a legal obligation on employers to provide software which is easy to use and suitable for the task.
More usable systems meet user and organisational needs better and:
- avoid recycling of analysis, design and implementation, thus reducing development and maintenance time and cost;
- are easier to understand and use, thus reducing training costs;
- improve the quality of life of users by reducing stress and increasing satisfaction;
- significantly improve the productivity of users and the operational efficiency of organisations;
- increase the competitive edge of the producers of the systems.
In order to decide whether to adopt a user-centred approach, it is necessary to assess the benefits and the costs. User-centred design can provide benefits in four areas:
- reduced production costs: the overall development times and costs can be reduced by avoiding over design and reducing the number of changes required late in design;
- reduced support costs: systems which are easier to use require less training, less user support and less subsequent maintenance;
- reduced costs in use: systems better matched to user needs improve productivity and the quality of actions and decisions. Easier to use systems reduce stress and enable workers to handle a wider variety of tasks;
- improved product quality: user-centred design results in products which have a higher quality of use and are more competitive in a market which is demanding easier to use systems.
The complete benefits of user-centred design come from calculating the total life-cycle costs of the product including conception, development, implementation, support, use and maintenance. To justify the costs of user-centred design at a particular stage of development, requires explicit identification and specification of the usability requirements prior to development, so that the costs of user-centred design activities can be balanced against the penalties for failing to meet usability objectives.
User-centred design processes are characterised by:
- an appropriate allocation of function between user and system;
- iteration of design solutions;
- the active involvement of users;
- multi-disciplinary design teams (including both technical and human factors personnel).
At each stage of design, user-centred activities are essential in order to understand and specify the business, user and organisational needs, so that potential design solutions can be evaluated against these needs. There are four essential types of activity:
- understand and specify the context of use: the nature of the users, their goals and tasks, and the environment in which a product will be used;
- specify the business, user and organisational needs in terms of effectiveness, efficiency and satisfaction; and the allocation of function between users and the system;
- produce designs and prototypes of plausible solutions;
- evaluate solutions against user criteria, preferably by testing them with representative users.
If usability evaluation is left until just before release, there will be no chance to make any significant changes in design to correct deficiencies. In order to achieve a usable product, it is important to begin the cycle of understanding, specifying and evaluating usability by using simple mock-ups at the earliest stages of design.
|
feasibility |
prototype |
release |
|
|
Understand context |
X |
X |
|
|
Specify usability |
X |
X |
|
|
Build solution |
X |
X |
|
|
Evaluation by users |
X |
X |
The table shows typical stages in the lifecycle when particular user-centred activities are performed. For most cost-effective design feedback, repeated evaluation with 3-5 users is recommended rather than less frequent evaluation with more users. However, to be confident that usability objectives have been achieved, a final evaluation with 10 or more users will be required.
Preparing for user-centred design
- Usability process maturity assessment
- Identify business and organisational needs and usability objectives
UCD activities during feasibility
- Context of use study
- Simple prototyping
- Scenario-based elicitation of requirements
- Usability objectives - definition and refinement
Evaluation of realistic prototypes
- Implementation of ergonomic principles and standards
- Measure whether usability targets have been achieved
Release and beyond
- Check if usability targets can be maintained
- Refine specification for next release
Usability Support Centres
Usability assessment is a way of using methods and measures to ensure that your product remains focused on the needs of the users from the start of the design cycle to the end.
In today's marketplace products must accurately and efficiently reflect the requirements of their users in order to remain competitive. Usability assessment methods provide the means to accomplish this.
Usability assessment provides a cost effective way of ensuring that products meet users requirements in terms of ease of use and ability to carry out a task. The return on the initial investment can be considerable, identifying potential problems early and pointing out possible solutions.
The cost of fixing a usability fault late in the cycle can be an order of magnitude greater than if it was fixed early in the cycle.
Although usability assessments work best with development methods in which early delivery of complete or semi-complete prototypes takes place, this is not the whole story. Much can also be learnt from considering previous versions, competitors' products, and proof of concept vehicles.
The European Usability Support Centres offer a range of methods that can be applied throughout the lifecycle. These methods are grouped and related to design phases as shown in the table below. Further explanation of these approaches and associated methods can be found in the guidebook on Usability Assessment. Some methods generally require low resources in manpower and equipment; others may require high resource utilisation.
Group |
Phase |
Resources needed |
Purpose |
Usability Context Analysis |
inception |
low |
planning |
Design guidance |
design |
low |
input |
Heuristic Assessment |
design/test |
medium |
diagnosis |
User Performance Assessment |
test |
medium |
measurement / diagnosis |
User Subjective Assessment |
test |
low |
measurement / diagnosis |
Model Based Assessment |
design |
high |
input |
These approaches encompass a range of methods that are currently in use in industry. You don't have to use all of them. Different methods identify different problems. Some methods apply to different stages in the development lifecycle. For example some are better suited to the early stages of the development cycle and others towards the end of the lifecycle. The methods selected by the European Usability Support Centres have been shown to work well in industry; your starting set should be those methods which best fit to your company or project way of doing things. Representatives from the support centres can help you to select the methods that are most appropriate to your needs. As you gain experience you can start to set more ambitious goals for usability assessment and 'buy into' other methods. Experience has shown us that the most successful route to process improvement is to ensure that all assessment methods fit into the company culture from the start.
Some usability assessment methods are developed in a 'light' version that can be used quite effectively with minimal training. A human factors expert may be necessary initially to establish the usability processes and later can provide support for more complex assessment techniques.
Quite right. We have two approaches to this problem: understand the user, and employ efficient and reliable methods.
- Know thy user: the Context of Use analysis method enables the design team to focus on exactly who is expected to be using the system, for what purpose, and under what circumstances. Not only can user testing be guided by this knowledge, the team as a whole has a better understanding of what the targets are.
- Reliability: the methods offered have gone through an extensive period of industrial testing and are, if used properly, the most reliable tools available. This means you can achieve realistic results with small numbers of end users testing the system.
Contact your local European Usability Support Centre at one of the addresses at the end of the User-centred Design section above.
When you design a multimedia system you must pay attention to the entire context in which the system will be used in terms of the users and what they will do with the system, as well as technical aspects such as what platforms the system is likely to be running on. This is what is known as contextual design. It should be noted that using sophisticated technology is not sufficient in itself for achieving quality.
Yes, design standards are available. However the real challenge lies in how the content providers and the people who actually put the material together take care of both the aesthetics and the ergonomics of the system being developed, with due care being paid to prevailing conventions and guidelines. You won't find that sort of information in a standard or style guide.
Principles of design, and design recommendations, as in the ISO 9241 standard, can be very useful for explaining the design space available to a designer. These standards do not however assist in making design decisions involving areas like:
- navigation structures;
- information linking;
- non-graphical input and output;
- task design for people with special needs.
No, we're interested here in the main features which are essential for multimedia products: easy to understand design principles and design conventions. Our focus is on design requirements and design features of the end products of multimedia development efforts.
Yes, indeed there are a lot of definitions around. What underlies most of them is the concept of a special purpose consumer product which presents and accepts domain-specific information by means of simple and familiar interactions with the user. Sound, moving images, hyperlinks: all these are included in this conception of multimedia as a type of electronic book.
Not only the up-to-date Graphical User Interfaces (GUIs) involving graphics, images and animation! The guidebook also includes advice on how to design for multimedia with Character-based User Interfaces (CUIs), as well as interfaces that use speech recognition, and output by means of reproduced or synthesised speech.
This is one of the challenges of multimedia. Well-designed multimedia interfaces also offer customisation options never dreamt of before. We have to consider interfaces that are customised on behalf of the user (for instance, an Internet provider), and interfaces which the users can customise for themselves directly. This also includes interfaces customisable for people with special needs. The aim of customisation is to create an interface that allows the user to make good, informed choices that will assist the user's work. This area is at the forefront of contextual multimedia design.
Typical application categories and example systems might include:
- CUSTOMER INFORMATION: hotel information; shop or catalogue; tourist information centre.
- LEARNING SYSTEMS: school; university; vocational education; short training courses.
- CULTURAL/COMMUNITY
- INFORMATION SYSTEM: museum guide; civic information.
Well, each design activity is in itself a voyage of discovery, from which you and your organisation will learn a lot for future multimedia design activities. However, we realise that design support must be given in terms of examples or scenarios for actual use in order to be meaningful. It's up to you to abstract the design principles from your experience and to put them into your own organisation's design guide which can then be used for future systems.
We don't mind! We positively encourage it, as a way of your organisation getting the feeling that they 'own' the approach we advocate.
You may obtain the Design Guide for Multimedia from your nearest Usability Support Centre at one of the addresses at the end of the User-centred Design section above.
INUSE ('Information Engineering Usability Support Centres') was a European Commission supported project. The major objective of INUSE was to set up a network of Usability Support Centres across Europe to assist both companies and projects within the EC Telematics Applications Programme.
To provide information on usability, INUSE developed a series of Technical Guides. Whilst these were published in 1996, readers of El.pub may still find then useful. They are available for download as PC-zipped Word documents.
User Centred Design - an overview of the most cost effective methods for incorporating user requirements and usability into product and system design. Word 6 file PC zipped 100K
Usability Assessment - management guide to specifying, designing and measuring usability, obtaining feedback on the design, and using ergonomic standards. Word 6 file PC zipped 97K
Design Guide for Multimedia - introductory design guide with state-of-the-art guidelines for designing effective and appealing user interfaces for multimedia applications. Word 6 file PC zipped 116K
Organisations offering usability services - catalogue of organisations providing usability services across Europe (including the European Usability Support Centres). Word 6 file PC zipped 129K
|
File
Downloads - Please note
|
| File downloads from the El.pub site are currently suspended - the links however have not been updated to reflect this. If you would like access to a particular download file - please email webmasters@elpub.org with a suitable request confirming a description of the file you wish to download. |
El.pub - Interactive
Electronic Publishing R & D News and Resources
We welcome feedback
and contributions to the information service, and proposals for subjects for
the news service (mail to: webmasters@elpub.org)
Edited by: Logical Events Limited - electronic marketing, search engine marketing, pay per click advertising, search engine optimisation, website optimisation consultants in London, UK. Visit our website at: www.logicalevents.org
Last up-dated: 16 February 2024
© 2024 Copyright and disclaimer El.pub and www.elpub.org are brand names owned by Logical Events Limited - no unauthorised use of them or the contents of this website is permitted without prior permission.