Avoiding Bias

If questions are biased or leading in any way, they will steer a respondent toward the response that is considered socially desirable. This can occur either in the question itself or by limiting the types of response options that you provide. Below you will find some brief example of bias in questions. For more detailed tips for how to avoid bias, please see the survey design resource.

Examples of bias in survey questions

Leading Question

Biased Question:

Medical doctors claim that people who belong to a fitness club are healthier than those who do not. Do you plan on joining a fitness club this year?

This question is biased because it pits the opinion of the survey taker against those of experts. To reduce bias consider wording the question as follows:

Neutral Question:

Do you plan on joining a fitness club this year?

Question Response Order

Biased question order:

Please rate your opinion of the following on a scale of 1 to 5:

Final Grade
Course Instructor
Textbook

This question order injects bias because it begins by reminding the survey taker about their final grade in the course, which could influence their response to the next two questions. To remove bias consider placing the item that might lead to bias at the end of the list:

Neutral question order:

Please rate your opinion of the following on a scale of 1 to 5:

Textbook
Course Instructor
Final Grade

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