The magical sample size in polls
Now that political polls are a hot item, it is time to unveil the mysterious sentence that accompanies many public opinion polls (not only political) — This typically reads “the poll included 1033 adults and has a sampling error of plus or minus three percentage points”. No matter what population is being sampled, the sample size is typically around 1,000 and the precision is almost always “ۭ±3%” (this is called the margin of error). If you type “poll” in Google you will find plenty of examples. One example is the Jan 2, 2007 NYT Business section article “Investors Greet New … Continue reading The magical sample size in polls