The occurrence of errors per task was considered low in the group of young people in relation to the elderly
group. Considered a usability metric30, the error rate when performing tasks can reach a difference of up to 120%
between young and old. However, in this study, the error difference was higher. It was seen that during the initial
tasks, the errors of elderly participants were more evident due to unrecognized icons and problems in typing. Elderly
participants explored the interface more because they knew little about some of the features, as was the case in task
6, generating an error rate four times higher when compared to young users.
The error log was not considered an ideal metric to address both efficiency and effectiveness, as the operation of
the interface caused many touches on elements and functions that were not needed at a particular time, but that
somehow helped users learn paths by heart and remember features that would be required for future tasks. Elderly
users pointed out that errors are a part of learning and declared at the end of the test that they were more confident,
because they learned new things.