Argus: Interactive a priori Power Analysis

TL;DR

Argus is an interactive tool that helps HCI researchers explore and visualize statistical power for experiment design, enabling informed decisions on sample size considering various confounds and effect sizes.

Contribution

We developed Argus, a novel interactive tool that simulates data and visualizes power to assist researchers in designing experiments with appropriate sample sizes.

Findings

Argus effectively visualizes power across different scenarios.

Researchers found Argus helpful for understanding trade-offs in experiment design.

The tool supports more informed decision-making in HCI experiments.

Abstract

A key challenge HCI researchers face when designing a controlled experiment is choosing the appropriate number of participants, or sample size. A prior power analysis examines the relationships among multiple parameters, including the complexity associated with human participants, e.g., order and fatigue effects, to calculate the statistical power of a given experiment design. We created Argus, a tool that supports interactive exploration of statistical power: Researchers specify experiment design scenarios with varying confounds and effect sizes. Argus then simulates data and visualizes statistical power across these scenarios, which lets researchers interactively weigh various trade-offs and make informed decisions about sample size. We describe the design and implementation of Argus, a usage scenario designing a visualization experiment, and a think-aloud study.