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?
Do you see any 'filtering' process that might affect the sampling of the population?
not sure what u mean
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.
The results of this poll are likely to be biased for several reasons:
1. Self-selection bias: This poll relies on voluntary participation, meaning only those who feel strongly about the issue are likely to call and express their opinion. As a result, the sample of participants is not representative of the entire population who may hold a stance on handgun control. People who are motivated or have strong opinions on either side of the issue are more likely to call, while others may choose not to participate.
2. Cost and accessibility bias: The fact that participants are charged 50¢ for the first minute can create a financial barrier, potentially discouraging some individuals from calling. This could disproportionately affect individuals from lower-income backgrounds who may not be able to afford the cost or perceive it as a waste of money. Consequently, the poll may not reflect the opinions of those who are unable or unwilling to pay for participation.
3. Sampling bias: Since the poll is advertised in a specific newspaper, it primarily attracts readers of that particular publication. This can result in a skewed representation of the population, as readers of a specific newspaper may hold different opinions compared to the general population. Additionally, the poll only targets those who actively read the want ads section rather than the entire readership of the newspaper.
It is important to note that conducting a scientifically rigorous poll requires using random sampling techniques, ensuring a representative sample, and minimizing sources of bias. However, the design of this poll, with its self-selected and potentially biased methods, is not likely to yield reliable results that accurately reflect public opinion.