End-user customization of affective tactile messages: A qualitative examination of tool parameters

Vibrotactile (VT) signals are found today in many everyday electronic devices (e.g., notification of cellphone messages or calls); but it remains a challenge to design engaging, understandable vibrations to accommodate a broad range of preferences. Here, we examine customization as a way to leverage the affective qualities of vibrations and satisfy diverse tastes; specifically, the desirability and composition of VT customization tools for end-users. A review of existing design and customization tools (haptic and otherwise) yielded five parameters in which such tools can vary: 1) size of design space, 2) granularity of control, 3) provided design framework, 4) facilitated parameter(s), and 5) clarity of design alternatives. We varied these parameters within low-fidelity prototypes of three customization tools, modeled in some respects on existing popular examples. Results of a Wizard-of-Oz study confirm users´ general interest in customizing everyday VT signals. Although common in consumer devices, choosing from a list of presets was the least preferred, whereas an option allowing users to balance VT design control with convenience was favored. We report users´ opinion of the three tools, and link our findings to the five characterizing parameters for customization tools that we have proposed.