From the Preface to the print text:

This book is designed to teach presentation skills to students of technical communication, whose careers will involve making complex scientific and technical information accessible to a variety of audiences (including non-technical, lay audiences). Most technical communicators are very good at doing their job when it comes to technical writing but often lack the same skill when the task involves presenting material orally. Although this book is designed primarily for the working technical communicator and for technical communication students, science and technology professionals will also find the concepts in this book extremely useful in terms of how to present expert knowledge to general audiences.

The current text focuses exclusively on technical communication and provides a rich, interdisciplinary approach to the subject. Unlike general speech texts, where examples are taken from a wide variety of settings, examples in this book are drawn especially from the areas of science and technology. And, especially in certain chapters, this text offers a rhetorical perspective, addressing certain basic presentation types but also being broad enough so these concepts and techniques can be applied in a variety of settings. For no matter how much a textbook tries, no one book can capture the unique situations and types of presentations that take place from job to job or from organization to organization. Thus, a rhetorical approach, balanced with some specific examples and outlines, provides the most useful tool for learning about oral presentations in technical communication.