Name: _____________________________________ Class: _______________ Date: _______________
Single-Blind Experiment – Does Brand Name Matter?
One problem that can occur in psychological research is a self-fulfilling prophecy, which is when expectations influence behavior. For example, if participants know they’re receiving antidepressants they might begin to feel less depressed because they expect the drug to work. One way of avoiding the self-fulfilling prophecy is by using a single-blind experiment in which participants are blind to the type of treatment they receive, but the experimenter is aware of which treatment each participant receives.
People often have a preference for one brand of food or beverage over another, but what creates that preference? Is it the quality and taste of the product, or is it all in the marketing? In this single-blind experiment we will attempt to eliminate the self-fulfilling prophecy by making participants blind to the brand of the product.
Hypothesis: [Read the Preparation and Procedure sections, then write your hypothesis here.]
Gather three varieties of chocolate chip cookies. At least one should be a well recognized brand name, and least one should be a store brand. Be sure that all three products are as similar as possible (e.g., all regular chocolate chip cookies from the cookie aisle – not chewy, double chocolate chip, etc).
Place each brand of cookie into separate re-sealable plastic bags, and label the bags as “Brand X,” “Brand Y,” and “Brand Z.” The lead experimenter should record which brands correspond to X, Y, and Z and hide this information from participants.
1. Have each participant rate their opinion of each of the three brands on a scale from 1 to 10, then calculate and record the average opinion for each brand.
2. Have each participant taste and rate Brand X on a scale of tastiness from 1 to 10, then calculate and record the average tastiness rating for Brand X.
3. Repeat step 2 with Brand Y.
4. Repeat step 2 with Brand Z.
5. Compare the ratings for Brands X, Y, and Z, and then reveal the brand name of each product.
See original for results/observation chart set up (follow the link below)
1. What patterns do you notice in the data?
2. Did these patterns support your original hypothesis? If not, why do you think your hypothesis was not supported?
3. Based on the results of this study is brand loyalty due to taste or something else? Explain.
4. What would be the benefit of making this study double-blind? How would you make this study a double-blind study?
5. How might these findings apply in everyday life? Give an example.