Designing and Reporting Multi-Directional Tapping Tasks: A Systematic Review, Practical Guidelines, and a Configurable Testbed

Abstract

The Multi-Directional Tapping Task (MDTT) is used to evaluate pointing devices and interaction techniques with Fitts' law, but its procedure leaves implementation choices open. We reviewed 157 studies across conventional and extended-reality (XR) environments, examining apparatus, interaction modalities, task difficulty, target geometry, trial structure, feedback, performance measures, and analysis. Although studies shared a task core, they varied in Index of Difficulty, dimensions and units, target shape and count, movement handling, and feedback. Geometric and methodological analyses show that nominal difficulty, shape, and count do not fully specify the realized task; absolute amplitude and width, direction-dependent extent, selection sequence, and XR depth and visual angle can distinguish similar configurations. Integrating these findings with ISO procedures and Fitts' law methodology, we provide six recommendations, a planning and reporting checklist, and a configurable testbed that exposes core parameters and supports reproducible configurations. We identify evidence-supported defaults while emphasizing documentation over a universal configuration.