Aims of this Chapter Consider what doing interaction design involves Explain some advantages of involving users in development Explain the main principles of a user-centred approach Ask and provide answers for some important questions about the interaction design process Introduce the idea of a lifecycle model to represent a set of activities and how they are related Describe some lifecycle models from software engineering and HCI and discuss how they relate to the process of ID Present a lifecycle model of interaction design Summary What is involved in interaction design Design involves working on requirements, designing a solution, producing the solution and evaluating it.
Design is about trade offs – cost vs. effectiveness etc. and so key to design is generating alternatives.
Involving users and others in design process means that the designs and potential solutions need to be communicated to people other than the original designer. There are many ways of doing this.
The importance of involving users
The best way to make sure that development continues to take users activities into account is to involve real users throughout the development. In this way developers can better understand user goals leading to a more appropriate more usable product. It also assists in setting expectations of the user.
Expectation management is the process of making sure that the users view and expectations of the new product are realistic.
It is better to exceed user expectations than to fall below them.
There are several ways to set user expectations including
Involving them throughout the design and developing stages Have timely training Degrees of user involvement
User involvement depends on what is involved and the nature of the product, on one end of the scale you can have the user involved all the time on the other end of the scale you could keep them informed via newsletters
How actively users should be involved is a matter of debate, too much user involvement can lead to issues and not enough user involvement can lead to poor solutions.
What is a user centred approach
Three principles that lead to a user centred approach
Early focus on users and tasks – see goals below Empirical measurement – be able to measure what you are wanting to achieve Iterative design – perform design in small steps With an early focus on users and tasks it can be further broken down into categories
User tasks and goals are the driving force behind the development User’s behaviour and context of use are studied and the system is designed to support them User characteristics are captured and designed for Users are consulted throughout development from earliest phases to the latest and their input is seriously taken into account All design decisions are taken within the context of the users, their work, and their environment Four Basic activities of Interaction Design
Identifying needs and establishing requirements for the user experience Developing alternative designs that meet those requirements Building interactive versions of the designs Evaluating what is being built throughout the process and the user experience it offers Some practical issues that need to be considered Who are users? What do we mean by needs? How do you generate alternative designs? How do you choose among alternatives? Lifecycle models: showing how the activities are related Some software engineering lifecycle models
The waterfall lifecycle model The spiral lifecycle model Rapid applications Development Agile development Lifecycle models in HCI
The star lifecycle model The usability engineering lifecycle Human centred design process for interactive systems Star Lifecycle Model
Star Lifecyucle Model
Does not specify any ordering of activities Activities are highly interconnected Evaluation is central to this model – whenever an activity is complete it must be evaluated Usability Engineering Lifecycle
Essentially has 3 tasks
Requirements Analysis Design / Testing / Development Installation ISO 13407 Human-centred design processes for interactive systems
International standard for providing guidance on human centred design activities.
Standard identifies four principles of human centred design
Active involvement of users and clear understanding of user and task requirements An appropriate allocation of function between users and technology The iteration of design solutions Multi-disciplinary design It specifies four human-centred design activities as being central to a system development project:
To understand and specify the context of use To specify the user and organizational requirements To produce design solutions To evaluate designs against requirements IMG
