In Fitts’ law research for pointing and selecting tasks, the multi-directional tapping task from ISO/TS 9241-411 has been widely used as a standard task. However, the ISO standard does not describe several task factors in sufficient detail, leading researchers to interpret and apply them independently in various ways. This study aims to investigate the effects of four task factors for multi-directional tapping task: error highlight, hover highlight, target shape, and number of targets. The experimental results indicated that all investigated task factors had significant effects on user performance and behavior, as reflected in both eye movement and mouse movement patterns. Our research findings can be helpful for researchers who want to evaluate the efficiency and effectiveness of interaction techniques and input devices for graphical user interfaces as a multi-directional tapping task protocol.

The multi-directional tapping task has long served as a foundational tool for evaluating pointing performance in human-computer interaction research. However, its transition from 2D interfaces to virtual reality (VR) raises challenges, especially in standardizing target depth. This study explores how target depth influences performance in VR, focusing on two common techniques: Raycasting and Virtual Hand. We conducted two controlled experiments (each with$\mathrm{n}=20$) to isolate depth effects. In Experiment 1, fixed target size led to visual angle (VA) shifts across depths, affecting performance. Both techniques performed best when VA was between$1-4^{\circ}$; Raycasting peaked at 2 m, Virtual Hand at$0.4-0.5 ~\mathrm{m}$. In Experiment 2, we controlled VA to isolate depth itself. Raycasting remained stable beyond 2 m but degraded at close range due to biomechanical limits. Virtual Hand remained sensitive to depth despite fixed VA, but differences were smaller, with throughput unaffected. These results suggest VA should be the primary parameter for standardizing the task in VR. Depth-specific evaluation remains necessary, except for Raycasting beyond 2 m. We provide depth-aware guidelines to improve standardization and comparability while aligning with ISO protocols.