Task-specific preference for numeric keypads

The present study examined task-specific user preferences for two numeric keypads. Eight scenarios describing numerical entry tasks were presented to 100 subjects. For each scenario, subjects were to choose the keypad of their choice between the ADD(ing machine) and TEL(ephone) arrangements. Scenarios including entering telephone numbers, the subject's personal identification number, other identification numbers, single digits, and mathematical calculations. A repeated-measures ANOVA showed a significant main effect for scenario on preference. When scenarios described telephone number entry tasks, preference for TEL was as high as 82%, whereas preference for TEL was as low as 50% when the scenario described mathematical calculations. It is suggested that task-specific preferences may be valuable design considerations, and could correspond to task-specific performance differences.