) Many research organisations give their interviewers exact scripts to follow when conducting interviews to measure opinions on controversial issues. (i) Give one type of bias which the research organisations are trying to minimise by using exact scripts for the interview. [1 Mark] (ii) Will the use of scripts completely eliminate this form of bias? Briefly justify your answer. [1 Mark] ) In March 2001, Princeton Survey Research Associates conducted a poll asking about the 2000 presidential election in America. The poll asked a random sample of 1200 adults Did you vote in the 2000 presidential election? 72% said yes and 28% said no. The actual voter turnout was 51%. What non-sampling error is most likely to explain the difference in the polled and actual figures? Justify your answer. [1 Mark] ) In a U.S. court case, Bristol Myers was ordered by the Federal Trade Commission to stop advertising that twice as many dentists use Ipana than any other toothpaste. Bristol Meyers had based their claim on a survey of 10,000 randomly selected subscribers to two dental magazines. They received 1,983 responses, with 621 saying they used Ipana and only 258 saying they used the second most popular brand. (i) Explain how selection bias may be a potential problem with the survey. [1 Mark] (ii) Explain why self-selection bias is not a potential problem with the survey. [1 Mark] (iii) Apart from selection bias, what is the main non-sampling error affecting the survey? Briefly justify your answer. [1 Mark] (iv) Why do the results of the survey not provide convincing evidence of Bristol Myers claim? Briefly justify your answer with reference to possible non-sampling error. [1 Mark]