The set questions and answers, regardless of how often they are pre-tested, constrain the range of responses possible. Surveys may, therefore, altogether miss those answers that do not fit the researchers' preconceived notions of what most people think. Imagine, for example, that you are asked to rank a list of issues in order of how much they concern you. The list might include issues such as the deficit, inflation, interest rates, unemployment, Canadian unity, violence, crime, aboriginal self-government, sexual equality, cultural sovereignty, and the environment. No doubt you could rank these issues.
Research shows that there can be significant differences.
Generally, it is more expensive to use open-ended questions. They are more difficult to code, quantify, compare and track over time, but they allow respondents to tell it their way. Closed questions inevitably constrain respondents and therefore limit the capacity of surveys to uncover the unexpected. Closed questions have a self-fulfilling effect. Some critics have gone further to suggest that the way these results are often presented has similar consequences on the opinions of Canadians.