3.4 Potential Problems with Sampling

• What is sampling bias?

  Sample not representative
• What are confounding variables?

  Variables distorting relationships
• Avoiding sampling bias is crucial for obtaining reliable results.


  True
• What is an example of undercoverage in a survey?

  Using only landlines
• What is response bias in measurement bias?

  Inaccurate answers by respondents
• What is social desirability bias?

  Answers for social approval
• What is an example of a confounding variable in a study between coffee and heart disease?

  Smoking
• What is the definition of sampling bias?

  Sample not representative
• Nonresponse bias occurs when selected individuals do not participate in a survey.


  True
• What causes response bias?

  Inaccurate answers by respondents
• Undercoverage is a type of sampling bias
• Undercoverage occurs when some members of the population are not included in the sample
• What is voluntary response bias?

  Self-selected participants
• Voluntary response bias occurs when all population members are surveyed.

  False
• Avoiding measurement bias is crucial for reliable data.


  True
• Steps to minimize response bias in surveys:

  1️⃣ Use clear and unbiased questions

  2️⃣ Ensure anonymity

  3️⃣ Avoid leading respondents
• Controlling for confounding variables is essential to assess the effect of an independent variable
• What is the definition of sampling bias?

  Sample does not represent population
• What is voluntary response bias?

  Participants self-select to respond
• Underreporting alcohol consumption in a survey is an example of response bias.


  True
• Smoking is a potential confounding variable in the relationship between coffee consumption and heart disease.

  True
• Poorly worded questions are a type of measurement bias.


  True
• Pretesting surveys helps identify problematic questions and improve accuracy.


  True
• Measurement bias occurs when data accurately represents the population.

  False
• What is nonresponse bias?

  Individuals do not participate
• Match the type of sampling bias with its definition:

  Undercoverage ↔️ Some members excluded

  Nonresponse ↔️ Selected individuals do not participate

  Voluntary response ↔️ Participants self-select
• Measurement bias occurs due to systematic errors in the measuring process
• Respondents may underreport alcohol consumption due to social desirability
• Confounding variables are related to both the independent and dependent variables.

  True
• Avoiding sampling bias ensures accurate and reliable data.


  True
• Undercoverage occurs when some members of the population are excluded from the sample
• Measurement bias occurs when data does not reflect the true characteristics of the population
• Response bias can occur due to social desirability, recall errors, or misunderstanding questions
• Sampling and measurement biases can impact the validity of statistical inferences
• Match the strategy with its purpose in mitigating sampling bias:

  Random sampling ↔️ Ensures equal inclusion

  Representative sampling ↔️ Reflects population characteristics

  Avoiding undercoverage ↔️ Includes all relevant subgroups

  Minimizing nonresponse ↔️ Maximizes participation rates
• What does pretesting a survey involve?

  Identifying and fixing problems
• What are confounding variables?

  Factors distorting relationships
• How does undercoverage affect statistical inferences?

  Skewed estimates and errors
• Careful wording of questions is a strategy to reduce response bias