Noticing a difference depends on the starting point
Compare the same addition against different starting amounts.
The picture in words
- Smaller starting weight
- Add 10 g to 100 g, a 10% increase.
- Larger starting weight
- Add 10 g to 1,000 g, a 1% increase.
- Relative change
- The same addition produces a larger proportional change from the smaller starting point.
- Perception
- Noticing a difference also depends on the stimulus and conditions.
Reading the illustration
Compare the proportional change. Difference thresholds depend on the stimulus and conditions; the drawing is a conceptual example.
Try a question
Which starting amount receives the larger proportional change?
Show the explanation
The smaller amount does. The same addition forms a larger fraction of a smaller starting value.
Read the sources
- Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). Psychology 2e. OpenStax. https://openstax.org/books/psychology-2e/pages/5-1-sensation-versus-perceptionSelected rendered passages on absolute and difference thresholds, reviewed in the topic-selection research.