Even though his scientific approach to polling has rendered great development to public opinion research area, Gallup's polling methodology has been criticized by many researchers (Hogan, 1997).

Hogan argued that Gallup's election and issue polls have committed so-called "nonsampling error." These sources of error include interviewing problems and imperfect interpretive theories. The race, gender, or class of interviewers and the context and timing of surveys were not systematically controlled. Also researchers recently pointed out that pollsters do not have explicit and sophisticated interpretive theories.
Furthermore, Gallup's polling did not control the problem of question wording. Question error results from not only the wording of individual questions, but also the order in which questions are asked and other factors that affect the context within which respondents interpret particular questions. However, in his book, The Pulse of Democracy (1940), Gallup said, "there will be no material difference in the result, no matter what wording is used."

In 1947, Gallup developed system of question design called "quintamensional approach" to solve the problem of question wording. Employing five categories of questions, including "filter" questions to assess knowledge and follow-up questions to find out the motivations and reasoning behind opinions, the "quintamensional approach" allowed a number of different dimensions of public opinion to be "intercorrelated, with a consequent wealth of data by which public opinion on any issue of the day can be described."

However, according to Hogan, the use of "filter" questions created unique and artificial interpretive contexts for questions that came later in the interview process. The whole approach also instigated bad practice in modern polling: the practice of informing respondents about an issue before asking their opinion.