As a mechanism for obtaining information and opinion, questionnaires have a number of advantages and disadvantages when compared with other evaluation tools. The key strengths and weaknesses of questionnaires are summarised in bullet points below. In general, questionnaires are effective mechanisms for efficient collection of certain kinds of information. They are not, however, a comprehensive means of evaluation and should be used to support and supplement other procedures for evaluating and improving teaching.
Advantages of questionnaires
- They permit respondents time to consider their responses carefully without interference from, for example, an interviewer.
- Cost. It is possible to provide questionnaires to large numbers of people simultaneously.
- Uniformity. Each respondent receives the identical set of questions. With closed-form questions, responses are standardised, which can assist in interpreting from large numbers of respondents.
- Can address a large number of issues and questions of concern in a relatively efficient way, with the possibility of a high response rate.
- Often, questionnaires are designed so that answers to questions are scored and scores summed to obtain an overall measure of the attitudes and opinions of the respondent.
- They may be mailed to respondents (although this approach may lower the response rate).
- They permit anonymity. It is usually argued that anonymity increases the rate of response and may increase the likelihood that responses reflect genuinely held opinions.
Disadvantages of questionnaires
- It may be difficult to obtain a good response rate. Often there is no strong motivation for respondents to respond.
- They are complex instruments and, if badly designed, can be misleading.
- They are an unsuitable method of evaluation if probing is required – there is usually no real possibility for follow-up on answers.
- Quality of data is probably not as high as with alternative methods of data collection, such as personal interviewing.
- They can be misused – a mistake is to try to read too much into questionnaire results.