With the 3rd edition for 2012 this text continues the tradition of providing a cross-section view of the various aspects of instructional design and technology (IDT). The very first concept in the introduction discusses the question "what exactly is IDT?", a question those in the field are continually asked. The approach to answer this question is to discuss various aspects of IDT using different authors who are experts in their own specialized areas within IDT. The opening sections on the definition and the history of IDT are of of particular value to both people in the field and laypersons. The remaining sections cover various aspects of IDT in detail, including how it fits in and impacts areas such as business, health care, education and the military. The third edition includes new information about important topics such as international multiculturalism, diversity and accessibility, and ethics. There is also a new discussion about the ever-increasing role of the design aspect of IDT. This remains an up-to-date and worthwhile reference to keep and continue to refer to even after you may have "had to read it" for an IDT course.