Haptic perception on touchscreens varies across fingers, yet little is known about how finger identity and multi-finger use shape tactile discrimination and user experience. We conducted two experiments with four haptic feedback. In Experiment 1, right-handed participants explored each of the ten fingers individually under stationary and moving conditions. Experiment 2 examined two-finger sequences with same participants. Results showed that moving exploration enhanced accuracy, confidence, and enjoyment, while stationary touch increased cognitive and physical load, especially for weaker fingers such as the left ring and pinky. The right thumb and index consistently performed best. In dual-finger trials, moving exploration improved second-finger performance, and adjacent same-hand pairs (e.g., Left Index–Left Thumb, Right Thumb–Right Index) yielded higher synergy. These findings highlight the role of finger anatomy, motion, and coordination, and provide concrete guidelines on which fingers (or combinations) and exploration modes to assign for haptic surfaces that optimize accuracy, comfort, and engagement.

In this paper, we compare eyes-free input gestures to gestures produced in the presence or the absence of a visual feedback for a single-handed mobile device interaction. We consider two gesture sets ((i) freeform gestures (operands, rationally invariant and mnemonic gestures) and (ii) mark-based gestures (on-axis rectilinear segments)) and two gesture beginnings (free: gesture can start from anywhere on the screen and bezel: gesture should start from one of the edge). Our findings indicate that gestures made in an eyes-free interaction were geometrically different from gestures generated in the presence or absence of visual feedback; they generated more directional movements around the y axis and had a lower recognition rate, which in itself was quite good (95.53%). Our findings also indicate that bezel gestures generated more phone movement and were less appreciated than those initialized freely. Freeform gestures were also preferred over mark ones. Based on those results, we propose five guidelines for eyes-free stroke gesture design, ergonomics, and recognizer development.

Touch knobs usually require visual attention when performing a targeting task. This can draw the user’s visual focus to the device, which is not desirable if the visual attention is needed elsewhere. In this work, we investigated the use of haptic feedback for touch knobs when performing another primary task that saturates the attention. In an experiment, we compare three potential tactile feedback designs to a no-feedback variant for a circular targeting task, while performing an attention saturating primary task. Our findings indicate that two investigated designs, namely, gradual+hapticObject and adaptive+hapticObject, providing the user with both haptic feedback on the objects and continuous haptic feedback through the trajectory, can serve as a reliable and effective mechanism for increasing the speed and reducing the mental demand for the secondary task while reducing visual distraction for the primary task.