Abstract. Numerous devices have been invented with three or more degrees of freedom (DoF) to compensate for the assumed limitations of the 2 DoF mouse in the execution of 3D tasks. Nevertheless, the mouse remains the dominant input device in desktop 3D applications, which leads us to pose the following question: is the dominance of the mouse due simply to its widespread availability and long-term user habituation, or is the mouse, in fact, more suitable than dedicated 3D input devices to an important subset of 3D tasks? In the two studies reported in this paper, we measured performance efficiency of a group of subjects in accomplishing a 3D placement task and also observed physiological indicators through biosignal measurements. Subjects used both a standard 2D mouse and three other 3 DoF input devices. Much to our surprise, the standard 2D mouse outperformed the 3D input devices in both studies.

The merits of user-driven design have long been acknowledged in the field of human–computer interaction (HCI): Closely involving target users throughout the lifecyle of a project can vastly improve their experiences with the final system. Thus, it comes as no surprise that a growing number of music technology researchers are beginning to incorporate user-driven techniques into their work, particularly as a means of evaluating their designs from the perspectives of their intended users. Many, however, have faced the limitations that arise from applying the task-based, quantitative techniques typically encountered in classical HCI research to the evaluation of nonutilitarian applications. The nature of musical performance requires that designers reevaluate their definitions of user “goals,” “tasks,” and “needs.” Furthermore, within the context of performance, the importance of creativity and enjoyment naturally supersedes that of efficiency, yet these concepts are more difficult to evaluate or quantify accurately. To address these challenges, this article contributes a set of key principles for the user-driven design and evaluation of novel interactive musical systems, along with a survey of evaluation techniques offered by new directions in HCI, ludology, interactive arts, and social-science research. Our goal is to help lay the foundation for designers of new musical interfaces to begin developing and customizing their own methodologies for measuring, in a concrete and systematic fashion, those critical aspects of the user experience that are often considered too nebulous for assessment.

We investigated dynamic target acquisition within a 3D scene, rendered on a 2D display. Our focus was on the relative effects of specific perceptual cues provided as feedback. Participants were asked to use a specially designed input device to control the position of a volumetric cursor, and acquire targets as they appeared one by one on the screen. To compensate for the limited depth cues afforded by 2D rendering, additional feedback was offered through audio, visual and haptic modalities. Cues were delivered either as discrete multimodal feedback given only when the target was completely contained within the cursor, or continuously in proportion to the distance between the cursor and the target. Discrete feedback prevailed by improving accuracy without compromising selection times. Continuous feedback resulted in lower accuracy compared to discrete. In addition, reaction to the haptic stimulus was faster than for visual feedback. Finally, while the haptic modality helped decrease completion time, it led to a lower success rate.