Size matters: performance declines if your pixels are too big or too small

TL;DR

This paper introduces a conceptual model linking pixel size to target acquisition performance, demonstrating that display size impacts user accuracy and speed, with implications for usability across various display types.

Contribution

The paper presents a new conceptual model predicting how pixel size affects user performance and proposes heuristics for maintaining usability across different display sizes.

Findings

Users are fastest on standard desktop displays.

Undershoots are common on small displays.

Overshoots are common on large displays.

Abstract

We present a conceptual model that describes the effect of pixel size on target acquisition. We demonstrate the use of our conceptual model by applying it to predict and explain the results of an experiment to evaluate users' performance in a target acquisition task involving three distinct display sizes: standard desktop, small and large displays. The results indicate that users are fastest on standard desktop displays, undershoots are the most common error on small displays and overshoots are the most common error on large displays. We propose heuristics to maintain usability when changing displays. Finally, we contribute to the growing body of evidence that amplitude does affect performance in a display-based pointing task.