Effects of Visual Interruptions on Task Times and Accuracies

Additional computer screens and visual displays are often used to increase operator efficiency while performing tasks that require vigilance and selective attention. However, this additional information comes to the operators (drivers, security officials, air traffic controllers etc.) at a cost. In general operators are forced to multitask but sometimes multitasking is not possible and interruptions of tasks occur. Multiple Resource Theory suggests that humans have limited capacity for information processing especially if the tasks require the same resource, in this case visual resource. In this study, the effect of visual interruptions on primary task performances (in terms of errors made), and interrupting task times and performances were analyzed. Lafayette Instruments' DIVID software was used as the primary task and MVPT-3 visual perception test were used as interrupting task. Thirty subjects participated in the experiments. Repetitive measures ANOVA were used to analyze the data. The results showed significant decrease in primary and interrupting task performances as well as increase in interrupting task times.