Examining a Population
The survey by Katherine & Pollard (2015) examines American’s beliefs and opinions regarding contentious issues in public debate, specifically their opinions with regard to legalization of gay marriages. The survey was carried out following an announcement by the Supreme Court over a decision to legalize same-sex marriages in 24 states in late 2014. Following the announcement, researchers were keen on determining the public opinion over the controversial issue. Researchers asked two questions to respondents; first, they sought to know whether the sample of respondents were in favor or against the legalization of same-sex marriages, and second, asked the respondents whether the matter should have been left at the discretion of various states or the Supreme Court to decide according to the U.S. constitution. The sample of respondents were derived from different states so as to yield a fair representation. In addition, respondents had to be over 18 years of age (Katherine & Pollard, 2015)
The results indicated that a majority of Americans support the legalization of same-sex marriages. The figures indicate that 62.4 percent of those sampled support same-sex marriages. The margin of error during sampling was taken as +/- 1.2 percent. On the other hand, majority of those sampled (54.9 percent) support the involvement of the Supreme Court dealing with the divisive matter compared to state-by-state basis. In other words, majority of respondents feel the issue of same-sex marriages can be handled best at the federal level. Margin of error was taken as +/- 2.6 percent. 17.7 percent of the respondents were unable to decide on whether the decision should be made by states or federal government while 27.4 percent were in favor of states. A comparison of opinions provided by 549 respondents in 2010 and 2014 indicates a change of opinion, generally in favor of same-sex marriages. In 2010, 50.8 percent supported same-sex marriages, compared to 64 percent (+/- 4.0 margin of error) who supported it in 2014. The confidence interval was taken to be 85 percent (Katherine & Pollard, 2015).
Confidence interval is used to show the degree of uncertainty related to a particular sample estimate of the population parameter (Rumsey, 2007). The confidence level shows the uncertainty related to a particular sampling method. A 95 percent confidence interval as reported above indicates that 85 percent of the interval estimates would include the population parameter or the population mean. The range of confidence interval is given by the sample statistic plus/minus the margin of error. The low confidence interval was taken due to the low level of sample included from the original sample taken in 2010.
Margin of error is the sampling error that may occur in the survey which is based on a sample of respondents and not the entire population like in a census (Rumsey, 2007). The margin of error gives the maximum differences by which the results of the sample may differ from results based on an actual population. In a survey, researchers collect data from a sample population and the results generalized across the entire population. From the above results, 62.4 percent of the respondents supported same-sex marriages, with a margin of error of +/-1.2 percent. This means that the number of respondents in favor of same-sex marriage could be anywhere from 61.2 percent to 63.6 percent in the actual situation. A smaller margin of errors indicates a higher accuracy of the survey. The results comparing opinions in years 2010 and 2014 give a +/- 4.0 percent margin of error. This indicates the results are less accurate due to the smaller sample of the population used (549 respondents).
Katherine, G. C., & Pollard, M. (2015, March 1). Gay marriage gains support, but it’s still a partisan issue. Newsweek. Retrieved from: http://europe.newsweek.com/gay-marriage- gains-support-its-still-partisan-issue-296338
Rumsey, D. J. (2007). Intermediate statistics for dummies. Hoboken, NJ: Wiley Pub.