An Internet poll conducted in the United Kingdom by Netdoctor.co.uk asked individuals to respond to an “emotional health survey” (see www.hfienberg.com/clips/pollspiked.htm). There were 400 volunteer respondents. Based on the results, the British Broadcasting Corporation (BBC) reported that “Britons are miserable—it’s official.” This conclusion reflected the poll responses, of which one quarter feared a “hopeless future,” one in three felt “downright miserable,” and nearly one in ten thought “their death would make things better for others.” Which of the following is not correct about why these results may be misleading?
a. Many people who access a medical website and are willing to take the time to answer this questionnaire may be having emotional health problems.
b. Some respondents may not have been truthful or may have been Internet surfers who take pleasure in filling out a questionnaire multiple times with extreme answers.
c. The sample is a volunteer sample rather than a random sample.
d. It’s impossible to learn useful results about a population from a sample of only 400 people.