Controlling the spatial dimensions of visual stimuli in online experiments

Area of Science:

• Human-computer interaction
• Psychophysics
• Vision science

Background:

• Online research offers advantages like rapid data collection and diverse participant access.
• A key limitation of online studies is reduced control over experimental conditions, particularly for human vision research.
• Precise control over angular stimulus dimensions is challenging in online settings.

Purpose of the Study:

• To examine three methods for estimating participant viewing distance in online research.
• To quantify the error in angular stimulus size introduced by each method.
• To provide guidance for implementing these methods in future online vision studies.

Main Methods:

• Evaluation of three distinct techniques for determining participant viewing distance remotely.
• Quantification of the resulting angular stimulus size error for each method.
• Analysis of the trade-offs, benefits, and drawbacks of each viewing distance estimation approach.

Main Results:

• All three methods yielded an average expected error below 20% of the intended stimulus size.
• The most effective method achieved an average error close to 10%.
• The study provides practical parameters and code to aid researchers.

Conclusions:

• Estimating viewing distance online is feasible with quantifiable error margins.
• The developed methods and provided resources can enhance the reliability of online human vision research.
• Researchers can select the most appropriate method based on their study's specific needs and acceptable error tolerance.