Interdigit Keying Intervals on a Membrane Keyboard

Abstract

Fifty-three company personnel were asked to perform several copying tasks using a copier with a flat membrane keyboard. The digit portion of the keyboard was a 3 x 4 keypad. The time it took to key in seven particular two-digit numbers was electronically timed and recorded. The longest keying time was 1.75 s. Age had a reliable effect, though very small. Those over 45 took .1 s longer on average. There was no gender difference in keying times. Various reasons for much longer than average times are discussed. It was also noted that horizontal keying movement seemed faster than vertical movement.