a. A survey of teenagers about their favorite colors
b. A survey of students about vacation policies in a school district
c. A survey of supermarket shoppers about products they would like to see added
d. A survey of bike riders on whether they wear helmets
Answer: When conducting surveys, bias is a critical factor that can distort results, making them less reliable. Bias occurs when survey responses are influenced by sampling methods, question phrasing, or respondent behavior. According to research from the Pew Research Center and academic studies in survey methodology, different types of bias can impact survey outcomes.
Understanding Bias in Surveys
Bias in surveys happens when the collected data does not accurately represent the larger population. Some common types of bias include:
Selection Bias: When the sample surveyed does not reflect the target population.
Response Bias: When respondents provide inaccurate or misleading answers due to external influences.
Social Desirability Bias: When people give answers they think are socially acceptable rather than their true opinion.
Let’s analyze the given survey options in light of these biases.
Analysis of Survey Options
A: A survey of teenagers about their favorite colors
✅ Least biased.
Teenagers are likely to answer honestly based on personal preferences.
There’s minimal external pressure influencing responses.
However, if the sample only includes a specific group of teenagers (e.g., only high school students), there could be some selection bias.
B: A survey of students about vacation policies in a school district
⚠️ Moderate bias potential.
Students have a vested interest in school vacations, which could skew responses toward longer breaks.
If only high school students are surveyed, the sample would not represent younger students who may have different needs.
C: A survey of supermarket shoppers about products they would like to see added
⚠️ Some bias possible.
Responses may reflect the preferences of frequent shoppers rather than all potential customers.
If the survey is conducted during specific hours, it may exclude working professionals who shop at different times.
D: A survey of bike riders on whether they wear helmets
🚨 Most biased.
Selection Bias: Only surveying bike riders excludes non-riders who may have strong opinions on helmet use.
Social Desirability Bias: Respondents may feel pressured to say they wear helmets even if they don’t because it is the socially acceptable response.
Limited Representation: The results would not reflect the views of pedestrians, drivers, or policymakers involved in helmet laws.
Conclusion: The Most Biased Survey
The survey most affected by bias is D: A survey of bike riders on whether they wear helmets because it suffers from selection bias and social desirability bias, leading to misleading results.
How to Reduce Bias in Surveys
To create more accurate surveys:
Use Random Sampling: Ensure a diverse and representative participant pool.
Avoid Leading Questions: Phrase questions neutrally (e.g., “How often do you wear a helmet?” instead of “Do you always wear a helmet?”).
Ensure Anonymity: People are more likely to answer truthfully if they feel their responses won’t be judged.
By applying these best practices, surveys can yield more reliable and actionable insights.
