Psychological Experiment

Display Polarity:
Dark vs. Light Mode

Measuring the impact of screen polarity on human typing speed and cognitive accuracy.

Executive Summary

This study investigated whether display polarity significantly affects typing performance. While the hypothesis predicted superior results in Light Mode due to higher contrast, statistical analysis via a paired t-test revealed no significant difference in speed or accuracy between modes ($p > 0.05$). Subjective feedback suggested that performance is heavily influenced by individual preference and confirmation bias rather than physiological optic response alone.

The Hypothesis

"Participants will exhibit faster typing speed and higher accuracy in Light Mode compared to Dark Mode."

Methodology Profile

  • Design Within-Group
  • Sample 10 University Students
  • Tool Monkeytype.com
  • Duration 30s / 200 common words

Experimental Variables

Independent Variable (IV) Display Mode (Light vs Dark)
Dependent Variables (DV)
Typing Speed (WPM) Accuracy (%)
Controlled Confounding Variables
Visual Acuity Mode Experience Keyboard (QWERTY/QWERTZ)

Statistical Results (Paired T-Test)

☀️ Light Mode
47.7
Mean WPM
93.4%
Mean Accuracy
🌙 Dark Mode
47.8
Mean WPM
94.1%
Mean Accuracy
Significance Check: p > 0.05

Results are not statistically significant. The null hypothesis is retained.

Subjective UX Analysis

Why users preferred Light Mode:
  • Better overall contrast and readability.
  • Mental model alignment (reminds them of MS Word/standard documents).
  • Feels "less refractive" on the screen.
Why users preferred Dark Mode:
  • Helps visibly catch and isolate prominent UI elements.
  • Lower luminosity reduces immediate eye strain.
  • General aesthetic comfort.

Behavioral Observations

Beyond the metrics, observational data revealed strong cognitive biases. Participants displayed varying levels of performance anxiety despite the low-stakes environment.

Crucially, elements of Confirmation Bias were observed: participants unintentionally exerted more effort on their pre-established "preferred" display mode to achieve desired outcomes.

Conclusion

While data showed a marginal advantage for Dark Mode in both speed and accuracy, the lack of statistical significance rejects the initial hypothesis.

Future scaling with larger sample sizes is required to separate genuine physiological advantages from subjective environmental factors and learned behaviors.