Photo: secretlondon123 (Flickr) Pollsters looking for the
opinion of the American public obviously can’t survey everyone.
But by surveying a smaller, random 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. Margin Of Error Along with the primary
result of the survey, you often hear what is called “the margin
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. How confident can the surveyor be about an estimated
margin of error? To measure this, surveys also have what is
called a “confidence le