The main goals of this chapter are to accomplish the following:
Reflect on what interaction design involves.
Explain some of the advantages of involving a range of people as participants in the interaction design process.
Explain the main principles of a people-centered approach.
Introduce the four basic activities of interaction design and how they are related in a simple lifecycle model.
Consider some practical questions about the interaction design process.
Consider how interaction design activities may be integrated into other development lifecycles.
Imagine that you have been asked to design a cloud-based service to enable people to share and curate their photos, movies, music, chats, documents, and so on, in an efficient, safe, and enjoyable way. What would you do? How would you start? Would you begin by sketching how the interface might look, work out how the system architecture should be structured, or just start coding? Or, would you start by asking people about their current experiences with sharing files and examine the existing tools, for example, Dropbox and Google Drive, and based on this begin thinking about how you were going to design the new service? What would you do next? This chapter discusses the process of interaction design, that is, how to design an interactive product.
Interaction design includes specific activities focused on discovering requirements for the product, designing something to fulfill those requirements, and producing prototypes for evaluation. It aims to develop interactive products to support the way people communicate and interact, and so identifying, understanding and engaging a range of stakeholders in product development is fundamental. This means that product development is directed by people-centred concerns rather than just technical concerns. But what kind of products are needed and how do we know? What is a “stakeholder”, how can they be identified, and how can they be involved in development? Will they know what they want or need if we just ask them? From where do interaction designers get their ideas, and how do they generate designs?
Interaction design is a design activity and so is about trade-offs—about balancing conflicting requirements. For example, one common form of trade-off when developing an interactive system is deciding how much choice is given to the user and how much direction is offered by the system. But how do you make that choice? Generating alternatives is also a key principle in interaction design. Generating lots of ideas is not necessarily hard, but how do you choose which of them to pursue?
In this chapter, we consider these kinds of questions, discuss people-centered design, and explore the four basic activities of the interaction design process. We also introduce a lifecycle model of interaction design that captures these activities and the relationships among them.