Effects of activation method and mental effort on touchscreen task performance for users with and without upper extremity motor control disabilities

The rise in popularity of touchscreens supports the need for improving the usability and accessibility of the technology for users with varying abilities. Touchscreen activation methods (tapping, take-off) can help address these issues but may have trade-offs (longer time to complete task). This study evaluated tapping and take-off touchscreen activation methods during a multi-item selection activity. Participants with (n = 10) and without (n = 10) motor control disabilities affecting upper extremity function (+MCD and −MCD, respectively) completed an experimental task to select four items from a list using either tapping or take-off activation with two different levels of mental effort (memorization vs. no memorization). Fewer errors (29 vs. 21 %, p = .018) but longer task completion times (14.3 vs. 9.04 s, p = .007) were observed for take-off vs. tapping. Error rate doubled for memorization compared to no memorization (33.5 vs. 16.5 %, p = .002). Both +MCD and −MCD groups had fewer errors using the take-off method, but tapping was preferred, had fewer misses and required less task completion time during a menu selection activity. For tablet touchscreen menu selection applications for individuals with and without upper extremity motor control disabilities, take-off activation method is more accurate than tapping though tapping is preferred, has fewer misses and requires less task completion time. Additional mental demand leads to an increase in the number of errors during touchscreen operation.