Questionnaires are a commonly used method of data collection in a wide range of fields from psychology to economics that offer researchers a highly structured technique of collecting data on particular issue or topic. Questions can either be open-ended, in which the respondent provides his own answer, or closed -- such as multiple-choice -- in which the respondent selects from a set of given responses.
Questionnaires are employed by researchers who wish to collect factual information regarding patterns, trends, perspectives, attitudes or behaviours of a particular group; they can also be used to identify shifts in these areas over a period of time. Questionnaires cannot, however, explore complex issues in great detail and, according to Roger Sapsford of the Open University and Victor Jupp of the University of Northumbria, are not recommended for use in controversial or sensitive issues, such as sexuality or religious beliefs.
As questionnaires can be posted out or e-mailed to respondents, they offer researchers the ability to reach people spread across a wide geographical area or who live in remote locations. Furthermore, as questionnaires do not require the presence of an interviewer, they can be completed and returned at a time that suits the respondent. However, questionnaires are not suitable for everyone, such as those with impaired vision, and should be kept relatively short to ensure a higher response rate.
Although questionnaires offer the researcher a choice of open-ended and closed questions, they do not provide an opportunity for interaction between the researcher and respondent. This means that a researcher cannot probe for further information on a particular question or issue of interest. Similarly, in cases in which the researcher is not present, a respondent who does not understand a question or cannot categorise his answer into the structured format has no opportunity to help or clarification.
As questionnaires tend to produce quantitative data, they are relatively easy to analyse, for example with the use of specially designed computer programs. Similarly, their results are easily comparable to other questionnaires, surveys or standardised research projects to gain an overall impression of a particular topic or issue. Questionnaires are, however, prone to low response rates, as participants may lack any incentive for completing the survey or be generally uninterested in the research topic. In addition, data analysis can become complex and distorted when respondents have misunderstood or incorrectly answered a question.