Describe how public opinion is measured and some of the challenges that arise with polling.Specifically,discuss what sampling is,why sampling is used,and how the problems of social desirability effects,selection bias,the bandwagon effect,and push polling undermine survey research.

There are five components to this question.
a.Sampling definition and goal: A sample is a small group selected by researchers to represent the most important characteristics of an entire population.Pollsters take a sample of the population and use it to make inferences about the preferences of the population as a whole.For a survey to be an accurate representation of the population,it must meet certain requirements,including an appropriate sampling method,a sufficient sample size,and the avoidance of selection bias.
b.Social desirability effects: The social desirability effect occurs when respondents report what they expect the interviewer wishes to hear or whatever they think is socially acceptable,rather than what they actually believe or know to be true.Political scientists have found that social desirability effects produce inaccurate survey results when the surveys include questions about sensitive issues for which individuals do not wish to share their true preferences.
c.Selection bias: Selection bias is polling error that arises when the sample is not representative of the population being studied,which creates errors in overrepresenting or underrepresenting some opinions.
d.Bandwagon effect: The so-called bandwagon effect occurs when polling results convince people to support a candidate marked as the probable victor.
e.Push polling: Push polls are not scientific polls and are not intended to yield accurate information about a population.Instead,they involve asking a respondent a loaded question about a political candidate designed to elicit the response sought by the pollster and,simultaneously,to shape the respondent's perception of the candidate in question.