ITap: Index Finger Tap Interaction by Gaze and Tabletop Integration

This paper presents ITap, a novel interaction method utilizing hand tracking to create a virtual touchpad on a tabletop. ITap facilitates touch interactions such as tapping, dragging, and swiping using the index finger. The technique combines gaze-based object selection with touch gestures, while a pinch gesture performed with the opposite hand activates a manual mode, enabling precise cursor control independently of gaze direction. The primary purpose of this research is to enhance interaction efficiency, reduce user fatigue, and improve accuracy in gaze-based object selection tasks, particularly in complex and cluttered XR environments. Specifically, we addressed two research questions: (1) How does ITap's manual mode compare with the traditional gaze + pinch method regarding speed and accuracy in object selection tasks across varying distances and densities? (2) Does ITap provide improved user comfort, naturalness, and reduced fatigue compared to the traditional method during prolonged scrolling and swiping tasks? To evaluate these questions, two studies were conducted. The first study compared ITap's manual mode with the traditional gaze + pinch method for object selection tasks across various distances and in cluttered environments. The second study examined both methods for scrolling and swiping tasks, focusing on user comfort, naturalness, and fatigue. The findings revealed that ITap outperformed gaze + pinch in terms of object selection speed and error reduction, particularly in scenarios involving distant or densely arranged objects. Additionally, ITap demonstrated superior performance in scrolling and swiping tasks, with participants reporting greater comfort and reduced fatigue. The integration of gaze-based input and touch gestures provided by ITap offers a more efficient and user-friendly interaction method compared to the traditional gaze + pinch technique. Its ability to reduce fatigue and improve accuracy makes it especially suitable for tasks involving complex environments or extended usage in XR settings.