The research on human expertise and complex skill acquisition that Wlliam G. Chase performed in the decade between publication of the classic chess studies he conducted with Herb Simon in 1973 and his untimely and tragic death has proven profoundly influential and enduring. Its impact spans disciplines that include Psychology, Computer Science, Education, Cognitive Neuroscience, Medicine, and Human Factors. It has contributed significantly to the emergence of Cognitive Engineering and has led to significant applications in the areas of training and instruction and knowledge-based "intelligent" computational systems. Its influence can be seen in current discussions of intelligence, heritability, intellectual potential, and achievement found in the contemporary popular press. The chapters in this volume document the enduring scientific contributions of William G. Chase to current knowledge and understanding of human expertise and skill acquisition and applications his work has supported. It will be of interest to those researching, studying, and working in the multiple fields that were greatly influenced by Chase's work.