The acquisition of typewriting skill

Abstract

Typewriting, like handwriting, is an example of a highly practiced motor skill. Professional typists spend about a year learning to type and then accumulate thousands of hours of practice during their working lives. This article describes data collected from 18 typists, ranging from beginning students in a typing class (about 1 keystroke/second) to expert professional typists (about 10 keystrokes/second). Expert typists were, of course, faster than beginners, but the rate and amount of improvement varied for different classes of keystroke sequences, and the pattern of keystroke times displayed qualitative changes with the acquisition of typewriting skill. For example, double letters, such as dd, were the fastest keystroke sequences for student typists, but they were among the slowest sequences for professional typists. In addition, the relative variability of the interstroke intervals decreased with learning. The most striking changes were for one-finger non-doubles, such as de, which were the most variable intervals for beginners and the least variable intervals for experts. Finally, the correlation between successive interstroke intervals for some letter sequences became more negative with learning. These experimental findings are interpreted in terms to two general changes during acquisition of typewriting skill: (1) the finger movements become less sequential and more overlapping with practice: (2) performance shifts from being limited by cognitive constraints in students, to being limited by motoric and physical constraints in experts.