The cost of an error

Fluency starts with arithmetic. An error costs more than the keystroke that made it: you notice it, which takes a moment; you press backspace, which is a keystroke; you retype the letter, which is another; and your rhythm, which was carrying the next three words, has to be restarted. A single wrong key costs somewhere between three and five keystrokes' worth of time. At forty words a minute that is about a second, and a typist who makes one error every twenty words is losing a fifth of their speed to corrections.

This is why every check in this course asks for accuracy first and speed second, and why the accuracy targets rise through it. It is not a moral position; it is the fastest route. A typist who slows down until they make almost no errors, then lets speed rise on its own, ends up faster than one who pushes speed and corrects as they go. The second typist plateaus, because their ceiling is set by how fast they can correct.

The result card shows a number called consistency. It measures how even your pace was: a hundred means every second of the attempt was typed at the same speed; a low number means bursts and stalls. Fluent typists have high consistency even at moderate speed, because their hands do not wait for their eyes. The drills in this unit are chosen so that an even pace is easy to find. Find it, then keep it.

calm even steady clear plain still