Final answer:
In a poll, likely voters represent the dependent variable, the outcome influenced by the independent variable, in this case, the candidates. Key concepts include independent variable, population, parameter, placebo, and valid poll design such as using a random sample without leading questions.
Step-by-step explanation:
In a poll asking which candidate likely voters will support in the next election, the voters represent the dependent variable because you are studying how this variable changes in response to different candidates. The following concepts are related to this topic:
- Independent variable: This is what the researcher changes or controls in order to see its effect on the dependent variable.
- Population: In terms of the poll, the population is the larger group that the sample of likely voters represents.
- Parameter: A summary measure that describes a characteristic of an entire population, such as the 50 percent in the government survey example.
When researchers administer a placebo, they aim to control for participant expectation, which could otherwise impact experiment results. In the case of a poll to determine voters' perceptions of the most important election issue, the random variable X would represent the number of voters who believe the economy is the most important. Remember that poll design requires a random sample without leading questions to be considered scientific.