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Chapter 1: Problem 22

Sample with caution According to a recent survey conducted by the Pew Research Center, it was found that, in \(2014,82 \%\) of all American internet users between the ages of 18 to 29 used Facebook. Why is it not safe to infer anything from this survey about: a. the proportion of the general population of all American internet users who use Facebook? b. the proportion of the general population of Americans who use Facebook?

Short Answer

Expert verified
The survey's sample is not representative of the entire population of internet users or all Americans, limiting inferential accuracy.

Step by step solution

01

Understanding the Sample

The survey considers only a specific group: American internet users aged 18 to 29. This is a subgroup and not representative of all American internet users or the general population.
02

Assessing Population Representativeness for Part a

For part a, the issue is that internet users between the ages of 18 to 29 may have different internet habits than other age groups, making them unrepresentative of all American internet users. Thus, using this subgroup to infer information about the entire population of internet users would be inaccurate.
03

Assessing Population Representativeness for Part b

For part b, the sample again does not include older age groups and non-internet users. Therefore, the sample is not representative of the general population of all Americans. This limits the ability to generalize the findings to the entire American population.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Population Representativeness
When conducting a survey, making sure that your sample accurately reflects the larger population is called population representativeness. Imagine you are trying to understand how many people in a whole country like ice cream, but you only ask people in a single city. This may not provide a true picture at all. Similarly, in the exercise, the survey only looked at American internet users aged 18 to 29, making it unrepresentative of all age groups or the wider American population.
  • This limited range means the results can be skewed, only reflecting the behaviors or habits of young people.
  • If all American internet users are not included in the sample, the survey answer cannot be applied to everyone.
  • It is crucial to have a diverse sample that includes various age groups, backgrounds, and demographic factors.
By ensuring population representativeness, results become useful and trustworthy for making more broad or general statements.
Demographic Segmentation
Segmentation based on demographic details is another layer to consider when creating a representative sample. Demographic segmentation involves splitting a population into smaller groups based on characteristics like age, gender, or income. Think of it like cutting a pie into different slices, each one representing a specific group within the population.
  • In the survey from our exercise, the segmentation focuses solely on age - adults aged 18 to 29.
  • This single segmentation omits other important demographic variables like older age ranges or geographical diversity.
  • A lack of varying segments may lead to biased results that don't capture the full picture.
To design a well-rounded study, it's key to consider multiple demographic segments to better reflect the total population. This ensures more inclusive and balanced data that respects and represents all voices.
Generalization
Generalization is the process of applying findings from a sample to a larger group. While it might be tempting to take the results of a sample, like the one in our exercise on young internet users, and say it applies to everyone, it's not always safe to do so.
  • Generalization only works well when the sample reflects the diversity of the entire population.
  • Without a representative sample, conclusions drawn cannot be safely applied to a wider population.
  • The exercise shows that using a small subgroup (young adult internet users) doesn't accurately reflect the behaviors or opinions of all Americans.
Therefore, careful attention must be paid to how surveys are designed and who is included. The aim is to ensure any generalizations made are valid and reliable. This ultimately helps in making informed decisions based on the survey data.

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Most popular questions from this chapter

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