統(tǒng)計(jì)學(xué)的成功案例和警示故事(編輯修改稿)
2025-05-27 05:58 本頁面
【文章內(nèi)容簡(jiǎn)介】 ed a random sample from the population of interest. How accurate could this sample possibly be ? Question 3 The results of this poll are accurate to within a margin of error of about % (95% confidence interval). nnnpp )?1(?2e r r o r ofM a r g i n ?????Moral of the story A representative sample of only a few thousand, or perhaps even a few hundred, can give reasonably accurate information about a population of many millions. CASE STUDY 4 Who Are Those Angry Women? “A wellconducted survey can be very informative, but a poorly conducted one can be a plete disaster.” Statistics: Concepts and Controversives, David S. Moore “The women who responded were fed up with men and eager to fight them. For example, 91% of those who were divorced said they had initiated the divorce. The anger of women toward men became the theme of the book.” Women and Love, Shere. Hite responsiveunresponsiveShere Hite sent questionnaires to 100,000 women asking about love, sex, and relationships. The Hite sample exemplifies one of the most mon problems with surveysthe sample data may not represent the population. Extensive nonresponse from a random sample, or the use of a selfselected (., allvolunteer) sample, will probably produce biased results. Moral of the story An unrepresentative sample, even a large one, tell you almost nothing about the population. Definition: Nonresponse bias can occur when many people who are selected for the sample either do not respond at all or do not respond to some of the key survey questions. This may occur even when an appropriate random sample is selected and contacted. Magazines, television stations, and inter websites routinely conduct the survey which is based on a nonrepresentative sample, usually those who feel strongly about the issues. The sample is called a selfselected sample or a volunteer sample which tells nothing about the larger population at all, it only tells you about those who responded. CASE STUDY 5 Does Prayer Lower Blood pressure? Prayer Can Lower Blood Pressure “Attending rel
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