Alphabetic Entry Procedure with Small Keypads: Key Layout does Matter

Abstract

Two experiments examined the entry of alphabetic characters on an enhanced telephone system. Size constraints with the overall unit resulted in a small keypad which restricted users to a one or two finger typing strategy. The first experiment compared the standard Sholes arrangement of keys (QWERTY), an alphabetically organized keypad (ABC) and a numeric code method of entry (NC) which utilized the touch telephone numeric pad. Thirty naive subjects were randomly assigned to one of the three conditions. Results showed that the NC method was significantly slower than the other approaches and was rated negatively by subjects. It was concluded that such an approach is unacceptable for a consumer product like the enhanced telephone. Experiment 2 further examined performance and preference for QWERTY versus ABC arrangements. Twenty subjects completed standardized text entry tasks on both arrangements with order counterbalanced. Performance was clearly faster on the QWERTY keypad and subjects recorded an overwhelming preference for it over the ABC arrangement, regardless of their previous keyboard experience. These results extend the superiority of QWERTY over ABC to small keypads and a restricted typing strategy.