Land Warrior: Effects of Size of Keyboard on Speed and Accuracy of Data Entry

The U.S. Army is implementing the Land Warrior (LW) system for use by individual infantry soldiers and their leaders. Among its many features, this system includes a wearable computer that allows soldiers and their leaders to communicate digitally. The principle method of data entry for this system is through a miniature keyboard that attaches to the user's forearm. The current experiment compared data entry speed and accuracy with the small (16 cm × 8 cm) LW (version 0.6) keyboard and a standard sized (45.5 cm × 17 cm) keyboard, with either one or two-handed data entry. The participants were 32 U.S. Military Academy cadets enrolled in a general psychology course. For speed data, there were significant main effects for both keyboard size and hands, and a significant interaction between the two variables. For accuracy measures, a significant main effect for hands was found. in general, participants were faster with the large keyboard, and more accurate with one hand, regardless of size of keyboard. Practical implications for LW implementation are discussed.