Book excerpt: This path-breaking book reviews psychological research on practical intelligence and describes its importance in everyday life. The authors reveal the importance of tacit knowledge--what we have learned from our own experience, through action. Although it has been seen as an indispensable element of expertise, intelligence researchers have found it difficult to quantify. Based on years of research, Dr. Sternberg and his colleagues have found that tacit knowledge can be quantified and can be taught. This volume thoroughly examines studies of practical intelligence in the United States and in many other parts of the world as well, and for varied occupations, such as management, military leadership, teaching, research, and sales.