Coupa: operation with pen linking on mobile devices

This paper proposes Coupa, a novel pen interaction design to support operations of users on portable devices. The design arranges a plurality of labels on the interface, each of which has an identity. The user forms a coupling by linking two graphical items together, and thus performs an action dependent on the identities of the coupled items. During the course of operation, any item on the screen is ready for linking and coupling. To reduce mal-operations, two principles for linking are proposed, with their effectiveness proved in the usability tests. Compared with traditional systems with hierarchical menu structure and point-and-click interaction, the proposed design prominently improves the efficiency and accuracy of pen-based systems with enhanced usability.