【英语时差8,16】公众投票的误差及可信度（上）

Pollsters looking for the opinion of the American public obviously can’t survey everyone. But by surveying a smaller, random¹ sample of the population they estimate the views of the whole population. The larger the sample, the more accurate the estimate is likely to be, but the results of every survey also include a second estimate as to the accuracy of the results. Along with the primary result of the survey, you often hear what is called “the margin² of error.” Imagine the following announcement: “Gallup poll finds seventy-five percent of Americans, plus or minus five percent, prefer hamburgers to hot dogs.” Headlines often ignore the “plus or minus five percent,” but that margin of error tells you how exact the results are. In this case, we learn that somewhere between seventy and eighty percent of Americans prefer hamburgers.

 

1 random   

adj.随机的；任意的；n.偶然的(或随便的)行动

参考例句：

• The list is arranged in a random order.名单排列不分先后。
• On random inspection the meat was found to be bad.经抽查，发现肉变质了。

2 margin   

n.页边空白；差额；余地，余裕；边，边缘

参考例句：

• We allowed a margin of 20 minutes in catching the train.我们有20分钟的余地赶火车。
• The village is situated at the margin of a forest.村子位于森林的边缘。