• Background
  • Instructions
  • Stimulus Settings
  • Method Settings
  • Experiment
  • Results

Background

The method of adjustment means just that. The observer controls the level of the stimulus and adjusts it to be at the perceptual threshold. The participant does so by increasing or decreasing the level of the stimulus until it feels like it is just at the detectable level. This is an intuitive measure for most participants because it mirrors many normal activities like adjusting the volume control on a radio or a dimmer switch on a light. In a light threshold study, the method of adjustment would ask the observer to adjust the light source to be the dimmest light that person can just detect. The advantage of this technique is that it can quickly yield a threshold for each participant, but a disadvantage is that it leads to great variance from one participant to the next and between successive trials for each participant.