1.3 Where Do We Go from Here?
| The primary goal of this book is to teach a way of thinking about VUI design. We focus on the underpinnings of the craft, basic design principles, and design methodology. Along the way, we present many examples and show you how to apply the principles in specific instances to address specific design issues. In the end, you should have a toolbox of techniques you can apply to many design situations. By itself, however, a toolbox can be dangerous. You cannot create an effective design that engages callers, meets their needs, and satisfies business goals by blindly applying rules of thumb. As you will see, there are two recurring issues that arise with every design decision at every step of the design process: consideration of context and understanding of the end user. By context we mean everything from high-level constraints such as business goals to low-level considerations such as how the wording of a prompt works in the context of the immediately preceding prompt and response. Understanding your end users includes assessing how they will react, what their needs are, and what their preconceptions are at each point in time. These considerations must play into every design decision you make, whether it is a decision to apply a principle, use a specific technique, modify it, or invent something new. Furthermore, technology is developing rapidly, enabling new, sometimes unanticipated possibilities. Leveraging new technological capabilities will create new challenges for the VUI designer. You must understand the fundamentals and design principles when you approach new situations. As a case in point, recent technology advances have made it possible to implement call routing applications of the type mentioned earlier. To achieve success with these systems, we had to learn new approaches to crafting prompts and new ways of creating the appropriate mental model for the caller. A mental model is the caller's internal model of how to interact with the system (Norman 2002; Preece, Rogers, and Sharp 2002). (The details of call router design are discussed in Chapter 12.) As you will see, a number of fields of knowledge contribute to the fundamentals of VUI design. In this book, four key areas emerge. Three of them we have already touched on:
The fourth area is technology. To make effective design decisions, you need some understanding of speech technology and must bring it to bear. Our description of technology gives you the necessary background to understand how to leverage the possibilities of the technology and compensate for its limitations. You will see the need for technology understanding when we discuss basic dialog strategy choices as well as design decisions for optimizing accuracy and recovering from errors, developing grammars, and tuning performance. This book is organized according to the design methodology we recommend. We and many others have applied this methodology to hundreds of successful deployments. Each major part of the book discusses one major phase of design. The first chapter in each part describes the relevant steps of the methodology. We follow that with a number of chapters discussing design principles and issues related to that phase of design. Each part ends with a chapter containing a detailed example, showing concretely how to apply the process steps and principles for that part. Before we dive into the methodology, a little more introductory material is needed. Chapter 2 provides an overview of speech technology and introduces some of the technical issues that figure into VUI design decisions. Chapter 3 introduces the general methodology that is covered in detail in the remainder of the book. |
