Investigating Single-Handed Microgesture Scrolling Techniques

Paper Title

Investigating Single-Handed Microgesture Scrolling Techniques

Publication Info

• Topic area: Interaction techniques for microgesture-based scrolling.
• Keywords: Microgestures, scrolling, user study, continuous input, interaction design, human-computer interaction, gesture sensing, usability, OptiTrack, transfer functions.

Background and Problem

• Problem / challenge: Existing research on microgestures has focused primarily on discrete inputs, leaving continuous input techniques like scrolling underexplored. Scrolling, a ubiquitous interaction, has not been experimentally examined for microgesture-based implementations.
• Significance: Scrolling is a frequent and essential interaction in consumer devices, and microgestures offer potential advantages such as reduced fatigue and eyes-free operation, making them suitable for emerging contexts like AR/VR and wearables.
• Motivation and related work: Prior studies have combined microgestures with other modalities for continuous input but lacked formal evaluations of microgesture-only scrolling techniques. Continuous scrolling has been studied for other modalities (e.g., touchscreens, joysticks) but not for microgestures. This paper addresses the gap by designing and evaluating microgesture-based scrolling techniques.

Solution

• Proposed approach: Development of four microgesture-based scrolling techniques leveraging Tap, Hold, and Drag gestures, with position and rate control mechanisms.
• Novelty:
  1. Introduction of four novel scrolling techniques using microgestures (TapPosition, HoldRate, DragPosition, DragRate).
  2. Experimental validation of microgesture-based scrolling techniques for the first time.
  3. Design insights for integrating microgestures into a comprehensive interaction vocabulary.
• Procedure and key techniques:
  • Characterization of scrolling into five components: Input Type, Direction, Clutch, Control Type, and Kinetic/Inertial.
  • Mapping microgestures to scrolling components and refining transfer functions through iterative optimization.
  • Conducting a user study with 24 participants across two tasks: Reciprocal Selection Task (target-based scrolling) and Counting Task (content-aware browsing).

Results

• Concrete findings:
  • HoldRate resulted in the fastest completion times and fewest overshoots for target selection tasks.
  • DragRate was most effective for browsing tasks, with fewer errors and higher subjective ratings for precision, efficiency, and comfort.
  • TapPosition consistently performed the worst across tasks.
• Advantage over baselines: DragRate and HoldRate outperformed TapPosition and DragPosition in both objective metrics (completion time, overshoots, errors) and subjective ratings (precision, efficiency, comfort, frustration, suitability).
• Experiments / evaluation:
  • Two tasks: Reciprocal Selection Task (144 trials per participant) and Counting Task (24 trials per participant).
  • Metrics: Completion time, overshoots, error counts, and Likert-scale subjective ratings.
  • Apparatus: OptiTrack system for microgesture sensing, Unity-based experimental setup.
• Limitations and future work:
  • Transfer functions could be further optimized or customized for users.
  • Vision-based sensing may introduce limitations in accuracy or tactile feedback compared to other technologies.
  • Future work could explore hybrid techniques, multi-finger scrolling, and comprehensive microgesture interaction vocabularies.

Summary

This paper introduces and evaluates four microgesture-based scrolling techniques, demonstrating their viability for continuous input tasks. HoldRate excels in target selection tasks, while DragRate is preferred for content-aware browsing. A user study with 24 participants highlights the strengths and limitations of each technique, providing insights into their usability and performance. The findings support the potential of microgestures as a standalone interaction modality, particularly for emerging contexts like AR/VR and wearables. Future research could refine transfer functions, explore hybrid techniques, and expand microgesture interaction vocabularies.