Studies on typing done at the University of California, San Diego (UCSD) are reviewed. The first of five chapters is a glossary of terms and classification of typing errors. Chapter 2 provides an overview of the variety of research approaches used to examine typing, including studies of continuous (transcription) and discontinuous (discrete trials) typing, the examination of typists of several skill levels, the analyses of error and of the interkeystroke time distributions, and examination of hand motions through video and film analysis. The computer simulation model of skilled typing developed at UCSD is briefly reviewed. Chapter 3 compares skilled and novice performances in discontinuous typing. A study of key-stroke timing in transcription typing is reported in chapter 4. Chapter 5 examines error patterns in skilled and novice transcription typing. Subjects in these studies ranged from novice to expert typists with typing speeds ranging from 12 to 112 words per minute. The studies focused on the influence of motor schemes and preplanning in the learning and performance of highly skilled motor activities; the role of overlapping, parallel motor activity; and the significant differences in typing styles. Their objective was a better understanding of the cognitive control systems for complex motor tasks. (YLB)