Two surveys: (A) 1,000 randomly chosen voters are mailed a survey; only 250 respond. (B) A magazine invites readers to mail in their opinions; 5,000 readers do.
Which best describes the dominant bias in each?
- Acheck_circle
A is nonresponse bias; B is voluntary response bias
- B
Both are voluntary response
- C
A is voluntary response; B is nonresponse
- D
Both are nonresponse
Explanation
In A, individuals were chosen but failed to respond (nonresponse). In B, individuals self-selected (voluntary response). These are different bias mechanisms.