People are better at juggling some types of multitasking than they are at others, according to a new study that has implications for distracted drivers. Trying to do two visual tasks at once hurt performance in both tasks significantly more than combining a visual and an audio task, the research found.
Alarmingly, though, people who tried to do two visual tasks at the same time rated their performance as better than did those who combined a visual and an audio task—even though their actual performance was worse.
“Many people have this overconfidence in how well they can multitask, and our study shows that this particularly is the case when they combine two visual tasks,” said Zheng Wang, lead author of the study and assistant professor of communication at Ohio State University. “People’s perception about how well they’re doing doesn’t match up with how they actually perform.”
Results showed that multitasking, of any kind, seriously hurt performance. Participants who gave audio directions showed a 30% drop in visual pattern-matching performance. But those who used instant messaging did even worse—they had a 50% drop in pattern-matching performance.
In addition, the findings show that technology companies need to be aware of how people respond to multitasking when they are designing products. For example, these results suggest GPS voice guidance should be preferred over image guidance because people are more effective when they combine visual with audio tasks compared to two visual tasks.
The study appeared in a recent issue of Computers in Human Behavior.