Everyday Research Methods

Facebook helps your self-esteem

CNN published an article with this headline: 

Study:  Facebook helps your self-esteem 

Before you read the article, consider:

1.  What kind of claim is the headline of this article making?  Causal?  Association?  Or Frequency?

 2.  What are the variables in the headline’s claim—what two variables will you expect to read about in the article?  

 

Will this man's self-esteem increase now that he has checked his Facebook page? 

 

Discussion questions for after you read:
a)    Decide what kind of study its authors conducted. Was it experimental or  correlational?  How do you know?

b)   Does the journalist’s causal headline fit with the kind of study the scientists conducted?  Why or why not? 

c)    Write a question that addresses each of the four big validities:  construct, internal, external, and statistical.  Which questions are you able to answer with the information in this story?  For which questions would you have to look up the original source? 

d)     What are the independent and dependent variables in this study?

e)    Was the study conducted as a between-groups or within-groups design?  What are the advantages to using this design, in the present case?

f)   Think about the comparison condition in this study.  Is a “computer turned off” condition the best comparison condition to use if the hypothesis is about the power of Facebook to raise self-esteem?

Online poll on disaster preparedness.

Soon after the great earthquake and tsunami in Northeast Japan, an article appeared on the CNN website about disaster preparedness in the United States:

Is “duck and cover” still the best we can do?

 This article reports an online poll conducted by CNN on people’s confidence in U.S. disaster preparedness.   It reports that 80% of the respondents did not have confidence in U.S. disaster preparedness. 

Questions:

a.  Read the first three paragraphs carefully.   What do you think of the sampling techniques used in this poll?  To what population can we generalize the results from this poll? 

b.  Your friend comments, “wow!  375,000 people responded to this survey!  We can definitely generalize this to the American population.”    What do you say? 

 

Schoolchildren practicing a "duck and cover" drill, designed to protect them from a nuclear attack.  (Photo: Bettmann/Corbis)

 

Suggested answers:

 a.  Notice that the poll was presented on the CNN website, which means that its sample was almost certainly self-selected.  (Another clue? A truly representative survey would never have called a random sample of 375,000 people—2,000 randomly selected people would have been plenty--see Table 6.1.) The upshot is that we have no idea to whom we can generalize the results, because we don’t know the characteristics of the type of people who choose to respond to this online poll.  They are cnn.com readers (who may be different from non-readers), and they also may have chosen to respond to the poll because they have a strong negative or positive opinion about the issue.

 b. Your friend is wrong; the number of participants in a sample has virtually nothing to do with the sample’s ability to generalize to a population.  What matters is not how many, but how.  If the sample is a probability sample, we can generalize to its population.  If not, we cannot.