System Delay and Navigational Structure for Web Applications and the Importance of Measuring Workload

Abstract

Myriad research suggests that delays associated with downloading of pages from server to client can have serious and deleterious consequences for usability. This has understandably led to design guidance suggesting that page download times be kept to a minimum in order to assure an optimum user experience. We argue that there may be some caveats to this rule, particularly when designing long applications, such as those used for data collection by customer service representatives. A series of three studies was conducted to test this assumption. Within each study, download pattern, navigation pattern, and total download time were differentially manipulated. Overall, it was found that an application downloaded in its entirety, rendered as a single page and navigated by scrolling, was subjectively preferred and scored lower on certain subjective workload subscales than applications downloaded incrementally, rendered as multiple pages and navigated by clicking. These results call into question the validity of design guidance focused exclusively on system delay time.