Note: This report was updated on Dec. 30, 2015 to reflect the January-July 2015 National Health Interview Survey estimates released on December 1, 2015. Telephone surveys face numerous challenges, but ...

Pew Research Center’s cross-national studies are fielded in a range of polling environments, from countries where telephone surveys are regularly administered to nations where face-to-face surveys are ...

Peter Kellner has written a challenging article with the straightforward title Down With Random Samples(Kellner, 2007). His opening lines are: “We all know what perfection looks like. It is a pure ...