The sampling method described suffers from a form of bias. Identify the bias, tell how the sample statistic might differ significantly from the population parameter, and suggest how the problem might be corrected.A pop music magazine asks readers to post comments on a website to voice their opinion on whether a state government should lessen intrusion into individual liberties by removing the ban on soft drinks in school vending machines. They find that 72% favor removing the ban on soft drinks in schools.

Question

What will be an ideal response?

Answer 1

There is undercoverage bias. Readers of the magazine are not representative of the general population, being younger and probably less conservative. There is voluntary response bias - those who feel strongly are more likely to respond. There is response bias. The wording of the question is designed to elicit support for removing the ban on soft drinks in schools. The rate of support in the sample for removing the ban is likely to be higher than the rate in the general population. A random sample obtained from a list of all voters would give a more accurate estimate. The question should also be worded in a more neutral way.