Multiple User Interfaces: Why Consistency is Not Everything, and Seamless Task Migration is Key

In this position paper, we argue that in the context of a user’s interaction with multiple platforms, consistency must be supported along with support for user’s task migration. We believe that the user should be able to perform a task using multiple user interfaces through an application that may or may not be similar at the interface level on each platform but, more importantly, one that supports seamless task migration. Further, we believe that consistency is desirable as long as it supports seamless task migration but should not dictate the design. We present examples of how successful multiple user interfaces have tackled the issue of consistency and discuss examples of why we should support task migration as a higher goal than consistency. We present a definition of task disconnect and its relationship to task migration. We also discuss some design issues related to consistency and task disconnect that must be considered in the development of multi-platform user interfaces.