Topics
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User-centred Design
User-centred Design (UCD) has already been introduced in Topic 1: Introduction. In this section we shall look at UCD in more detail and consider a particular approach. The approach, outlined in Figure 3.1, has been developed for this module to explain key HCI techniques and perspectives. It is therefore a framework for your learning in Block B of the module. However, this particular approach can be and has been used to design real systems.
Principles of UCD
Improving a Recipe
Having enjoyed a particular meal in a restaurant, you may want to
try and cook it at home. When you try out the recipe you may decide that
it was a success, but that there are certain things that could be improved.
The next time you try the recipe you will incorporate 'improvements' and
then decide whether they were a success or not. Hopefully, you can try
the recipe out on friends and incorporate their opinions as well.
It will be clear by now that UCD has a strong focus on users,
although as we shall see there are many differences in the extent and
nature of user involvement. The other core facet of UCD is that it is
highly iterative, so that 'testing can be done to check that the design
does indeed meet users' requirements' (Preece, 1994). This means that
a system is developed through a process of continuous refinement in which
a version of the system is designed, implemented in a prototype, evaluated
and then redesigned. We are thus brought back to the beginning of the
loop for another cycle of the iteration process, and this continues until
the system meets the requirements set down at the beginning. The whole
process from start to finish is often termed the development life-cycle.
Evaluation is the process which helps the designer see the strengths
and weaknesses of the prototype, which then informs the redesign. This
process of refinement is a very natural one and you should be able to
think of many ways in which you apply it in your own lives (see side panel
'Improving a Recipe', which considers the iterative refinement of a recipe).
Required Reading
Please now read Preece et al, Section 2.4, Designing HCI
and Section 17.3, Two Examples of User-Centred Design. In the first reading
Preece discusses some of the general principles of UCD. In the second,
two interesting UCD case studies are considered.
What principles of UCD does Preece introduce in the Readings?
- involve users
- design iteratively
- focus on user tasks
- evaluate using prototypes.
List the ways users are involved in the design process in the Case Studies in Preece et al.
The extent of user involvement varies significantly between different
approaches and different applications of UCD. At one extreme UCD can simply
involve designing a computer system from the user's perspective, and at
the other it can mean the involvement of real users as fully fledged members
of the design team. User participation is considered in more detail in
the topic on Methodologies for UCD. For now, all you need to appreciate
is that our approach involves basing design directly on the requirements
of the intended users of the system.
Our Approach to User Centred Design
Figure 3.1: Iterative, Staged Approach to User-centred
Design (processes are italicised and outputs of processes are non-italicised)
Our approach to UCD (see Figure 3.1) is staged as well as iterative. The stages are intended to be carried out in the order indicated by the numbers. However, stages are not fundamental to UCD. Most practitioners prefer to think in terms of design activities rather than stages. This is the case for our approach as well, because you don't necessarily have to carry out each stage in isolation. The designer can carry out the activities at various stages in parallel to some extent and may even return to previous stages. For example, this often occurs during stages 1 and 2, when the designer returns repeatedly to gather more data from the intended users whilst modelling.
Although stages can be done in parallel, the approach also
explicitly encourages iteration.
Which stages of our approach to UCD are explicitly iterative?
Stages 1 & 2
Stages 5 & 3
Stages 3, 4 & 5
Stages 1, 2, 3, 4 & 5
The stages are considered in detail in the following topics. To complete
the introduction to our UCD approach, the stages are outlined in the next
activity.
Match the UCD stage descriptions to the UCD stage names (1-5) in the selection boxes below, then check if you are right by pressing the 'feedback' button.
A single representation of the system requirements is created based on the needs of the users.
Sketches of the interface and who the users interact with it are drawn.
Whether the prototype meets the needs of the users is assessed.
System requirements are gathered through interviews with users and observations of them at work.
Progressively detailed prototypes are created.