University of Central Oklahoma
SPA Lab 1: Weber’s Law of Just-Noticeable Differences
Students react to a stimulus very differently based on one’s background and experience. These factors can affect how a person perceives things, especially when someone’s senses are being tested. Weber’s Law defines the correlation between concrete and alleged differences in stimulus strength (Coren, Ward, & Enns, 2004). The absolute threshold is the smallest amount of a stimulus that can be detected by the subject. Difference thresholds (just noticeable difference) are how much change there must be in the stimulus for a subject to detect the change. In this study, we allowed the participants to measure their just noticeable difference thresholds for the discrimination of line length using a psychophysical procedure known as the Method of Constant Stimuli (Coren, Ward, & Enns, 2004). Weber’s Law shows the relation between the size of the difference threshold and the magnitude of the standard. Ernst Heinrich Weber was one of the first people to approach the study of the human response to a physical stimulus in a quantitative fashion (Coren, Ward, & Enns, 2004). The method of limits offers the most direct connection with the idea of seeking a threshold. Method
Participants in this experiment included 28 students from the Sensation, Perception, and Action class at University of Central Oklahoma. Materials
Materials used in this experiment included: instructions, computer, paper, pen, and lab notebook. Design
As a class, we compared if Weber’s constant was within parameter. The independent variable was the group membership, whereas the dependent variable was the line size in pixels. We found the difference threshold for each ranges of the line length by obtaining the psychometric function. Procedure
During the experiment, the instructions directed each partaker to choose the...