No new data needs to be collected. Use the data from both of last week's
magnitude estimation experiments
Weber's Law Experiment: Use Forced Choice: Frequency Discrimination: ISLE 2.8b
Will Run 6 times
On the Stimulus Settings Tab Change (once per run):
Lab 1 (AM): 100, 200, 400, 800, 1600, & 3200 Hz (This will be your I)
Lab 2 (PM): 200, 400, 800 1600, 3200, & 6400 Hz (This will be your I)
Change no other settings
On the Method Settings:
Leave all the settings except:
Maximum value of Frequency Difference (Hz): 75
This is a Forced Choice method (Remember how to calculate these thresholds)
Using the Magnitude Estimation Data from Week 2
Paragraph describing procedure
Use graph from last lab. Does the graph fit better with Fechner's
or Stevens' predictions? Look at the shape. Consider all of the
data together. Do not answer for each data set separately but the
answer must apply to both results together.
For Weber's Law Experiment : Method of Constant Stimuli: Frequency Discrimination
Put data into the report.
Calculate the JND for each standard frequency
Forced Choice threshold equation
Your JND will already be ΔI
Convert to ΔI/I
Plot on a bar graph (What Excel calls a column graph)
X axis = I (Standard Frequency (Hz))
Y axis = ΔI/I
So 6 bars
Answer the following question: Does the data fit Weber's Law or not?
Why or why not?
Worth 25 points
Point: Develop your skills at interpreting graphs, in particular, in how
data relate to theoretical ideas.