We Gave Four Good Pollsters the Same Raw Data. They Had Four Different Results.

The New York Times:

You’ve heard of the “margin of error” in polling. Just about every article on a new poll dutifully notes that the margin of error due to sampling is plus or minus three or four percentage points.

But in truth, the “margin of sampling error” – basically, the chance that polling different people would have produced a different result – doesn’t even come close to capturing the potential for error in surveys.

Polling results rely as much on the judgments of pollsters as on the science of survey methodology. Two good pollsters, both looking at the same underlying data, could come up with two very different results.

How so? Because pollsters make a series of decisions when designing their survey, from determining likely voters to adjusting their respondents to match the demographics of the electorate. These decisions are hard. They usually take place behind the scenes, and they can make a huge difference.

If you’re interested in polling at all, this is a really great article.