Self-selection bias is systematic distortion caused by differences between people who choose to participate in a study and those who do not. These differences can matter when participation relates to the topic being measured. section 6.2.1
The risk is especially important for self-report measures. A survey about stress and time management, for example, may receive fewer responses from people with less free time, making the respondents unlike the broader group of interest. Treat participation patterns as a limitation when interpreting survey results and discussing them with stakeholders. section 6.2.1
Table 6.3 Pros and cons of self-report vs. behavioral measures
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Self-report measures
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Behavioral measures
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|---|---|
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✓ Easy to administer
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✓ Direct, precise measurement
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✓ Flexible questions and responses
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✓ Easily combined with other data sources
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✗ Prone to multiple forms of bias
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✗ Concerns about ethics and intrusiveness
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✗ Indirect measurement of a concept
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✗ Resource intensive to set up data capture
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Compare self-report and behavioral measures to see how selection-related bias fits among broader measurement trade-offs. section 6.2.1
