Question

Suppose that a newspaper published the following in a
boxed corner of the want ads section:
Should handgun control be abolished? You can call the shots if
you participate in our poll tonight. If yes, call 1-900-For-Guns.
If no, call 1-900-Ban-Guns. You will be charged 50¢ for the
first minute.
Why will the results of this poll be biased?

Answer 1

Do you see any 'filtering' process that might affect the sampling of the population?

Answer 2

not sure what u mean

Answer 3

If a poll should be unbiased, the sampling process should either be completely random, or efforts made to ensure that the sample represents the population in terms of demography, etc.

If you examine the sampling mechanism, do you see any group of people would be more likely to be sampled than others?

Notice where the ad was placed,
the language,
other conditions to respond to the poll, etc.

In non-unilingual countries, the language barrier can be overcome by employing multilingual peronnel to do phone polling or interviewing.