How do people really use text editors?

Keystroke statistics were collected on editing systems while people performed their normal work. Knowledge workers used an experimental editor, and secretaries used a word processor. Results show a consistent picture of free use patterns in both settings. Of the total number of keystrokes, text entry accounted for approximately 1/2, cursor movement for about 1/4, deletion for about 1/8, and all other functions for the remaining 1/8. Analysis of keystroke transitions and editing states is also presented. Implications for past research, editor design, keyboard layout, and benchmark tests are discussed.