Which Ice Cream Flavor Are You?

On By Beth Morling, University of DelawareIn Chapter 05; Identifying Good Measurement, Chapter 06; Surveys and Observations, Questions and Answers
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Many flavors, many personalities: How could we test whether an ice cream personality test is reliable and valid? Photo credit: Okanmetin/Getty Images

At the height of summer, we all start considering the same, timeless question: Can your personality can be accurately summarized by an ice cream flavor? This Buzzfeed poll asks you to answer a series of summer-activity-related questions and then delivers a verdict. Go take it yourself! I'll wait. 

The first time I took the poll, I answered the questions seriously and was told that I am characterized as "Coffee," along with this description: 

You’re a go-getter, a hard worker who doesn’t pause to reflect on what you have accomplished in the past because you are so focused on what you want to accomplish in the future. You seek to inspire the people around you and help to propel them to greater achievements. At the same time, you are approachable and kind rather than snotty and entitled. It’s basically the best of all worlds.

I sure felt good reading that personality description! The second time I took the quiz, I clicked on questions randomly haphazardly, just to see what other feedback there might be. This time I got "Chocolate", with this description:  

Mmm, you’ve got a truly rich and decadent side that you aren’t afraid to share. You make people feel good — really good. You’ve got a knack for excelling in social situations and know just how to be a crowd-pleaser. Keep doing your thing and living that luscious life.

Of course, nobody is going to mistake a Buzzfeed poll for a legitimate personality measure. But it does provide a fun way to consider issues raised in Chapters 5 and 6. Take the quiz yourself and then prepare these questions:
 
1.     What flavor ice cream did you get? What did the results say about you?
 
2.     Do you think this quiz is reliable? What kind of reliability is relevant for this measure? How would you empirically establish the quiz's reliability? Here's a hint: You'd start with a large sample of people and have them take this ice cream quiz, and then….. (what?)
3.  Now think about the measurement validity of this quiz. I'll narrow down the question for you here: Are people who score in the Coffee category actually more likely to be "hardworking," "inspiring," and "approachable," as the description suggests? How would you establish the criterion validity of this quiz? Here's a hint: You'd start with a large sample of people and have them take the ice cream quiz. You'd separate them into people who got the Coffee category and those who did not get Coffee. How should the Coffees be different from the non-coffees?
 
4.     What might we change about the quiz if we wanted to study ice cream preferences in a scientific way? 
 
5.  Read this description on the Barnum effect. Reflect on how the Barnum effect might be at play for people who take this Buzzfeed quiz. 
 

Many thanks for this idea to Josh Maxwell of the University of New Mexico!

 

Suggested answers to selected questions.

2. Test-retest reliability is the most relevant. To establish it, you'd have a large sample of people take the Buzzfeed quiz at one time point and record everyone's category (e.g., Coffee, Chocolate, etc.) Then you'd track down the same group of people again some time later (maybe 4 weeks later) and have them take the same quiz again. People who were scored Coffee at Time 1 should also score Coffee at Time 2, and people who were scored as Chocolate at Time 1 should also score as Chocolate at Time 2. (You'd compute the correlation between these two category assignments using Cohen's Kappa.)

3. To establish this criterion validity, you'd recruit a large sample of people and have them take the quiz, recording those who got Coffee and those who did not. Then you'd need to measure variables such as "hardworking" "inspiring" and "approachable." I'm not sure how to measure "inspiring" or "hardworking," but you could probably measure "approachable" using the Big Five trait of Agreeableness (here's one measure of that). If the Buzzfeed poll is valid, then a simple bar graph (and an independent groups t-test) should show that people who are assigned Coffee should score higher on agreeableness than people who were assigned some other flavor.