Demonstration 2.1 Method of Limits
Your participant should be blindfolded, so that he or she cannot see the numbers on the cups. For each of the eight series of the study, ask the participant to report if the water tastes sweet (Yes) or not (No) and record the response (Y or N) in the table below.
Ascending Series 1 (A1): Begin with Cup 1 (which should receive a “no” response) and continue giving the cups in an ascending order until the participant responds “yes”
Descending Series 1 (D1): Begin with Cup 10 (which should receive a “yes” response) and continue giving the cups in a descending order until the participant responds “no”
Ascending Series 2 (A2): Begin with Cup 2 and continue until the participant responds “yes”
Descending Series 2 (D2): Begin with Cup 9 and continue until the participant response “no”
Ascending Series 3 (A3): Begin with Cup 1 and continue until the participant responds “yes”
Descending Series 3 (D3): Begin with Cup 8 and continue until the participant responds “no”
Ascending Series 4 (A4): Begin with Cup 3 and continue until the participant responds “yes”
Descending Series 4 (D4): Begin with Cup 10 and continue until the participant responds “no”
A1 / D1 / A2 / D2 / A3 / D3 / A4 / D4Cup 1
Cup 2
Cup 3
Cup 4
Cup 5
Cup 6
Cup 7
Cup 8
Cup 9
Cup 10
For each series, determine the threshold by using the midpoint between the cups labeled “yes” and “no.” That is, if on series A1 the participant said “no” to Cups 1 through 5 and said “yes” to Cup 6, the threshold for that series would be 5.5 (or about 1.4 teaspoon per 16 ozs.). Write those thresholds in the spaces below and then take the arithmetic mean of the threshold estimates.
A1 / D1 / A2 / D2 / A3 / D3 / A4 / D4 / MeanValue