A website asks visitors to click "agree" or "disagree" on a controversial statement. Of 8,000 voters, 72% agreed.
The largest source of bias is
- Acheck_circle
Voluntary response bias
- B
Undercoverage
- C
Sampling variability
- D
Response bias
Explanation
Visitors self-select to participate; those with stronger views are more likely to vote. This is voluntary response bias.