[1] The article did not include any information on the size or make-up of the sample population, nor how much pressure the interviewer applied to receive a response.
[3] One exception, Stanley L. Payne, wrote about Gill's study in the 1951 The Public Opinion Quarterly journal article "Thoughts About Meaningless Questions" and called for further investigation into this type of non-sampling error.
[3] Despite Payne's call to action, pseudo-opinions remained largely unstudied until the 1980s,[6] but in 1970 Philip Converse postulated that answering "don't know" is seen by respondents as an admission of "mental incapacity".
[5] Their research found that pseudo-opinions are a significant source of error but not as prevalent as Hartley and Gill's studies suggested.
[10] A study by the University of Cincinnati found 20 to 40 percent of Americans will provide pseudo-opinions because of social pressure, using context clues to select an answer they believe will please the questioner.