In the 1936 U.S. presidential election, The Literary Digest mailed out 10 million questionnaires, of which 2.3 million were returned. Based on this , they predicted that Republican Alf Landon would win with 370 of 531 electoral votes ; he actually got 8. Research published in 1976 and 1988 concluded that non-response bias was the primary source of this error, although their sampling frame was also quite different from the vast majority of voters. Non responders have been shown to be associated with younger patients, poorer communities and those who are less satisfied and subsequently could be a source of bias by a study published by Imam et al. in 2014.
In the 1936 U.S. presidential election, The Literary Digest mailed out 10 million questionnaires, of which 2.4 million were returned. Based on these , they predicted that Republican Alf Landon would win with 370 of 531 electoral votes , whereas he only got eight. Research published in 1976 and 1988 concluded that non-response bias was the primary source of this error, although their sampling frame was also quite different from the vast majority of voters. Non responders have been shown to be associated with younger patients, poorer communities and those who are less satisfied and subsequently could be a source of bias by a study published by Imam et al. in 2014.
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