RESEARCH NOTES
DESIGNING A QUESTIONNAIRE
Ng Chirk Jenn,MMed(FamMed Singapore), Department of Primary Care Medicine, University of Malaya
Ng CJ. Designing a questionnaire. Malaysian Family Physician. 2006;1(1):32-35
In a survey, the researcher uses a questionnaire to gather information from the respondents to answer the research questions. A questionnaire is a very convenient way of collecting information from a large number of people within a period of time. Hence, the design of the questionnaire is of utmost importance to ensure accurate data is collected so that the results are interpretable and generalisable. A bad questionnaire renders the results uninterpretable, or worse, may lead to erroneous conclusions.
A survey can come in many forms: postal survey, telephone interviews, face-to-face interviews and internet surveys. Each type of survey requires a slightly different design. A self-administered questionnaire (e.g. postal survey) should have very clear instructions and questions, follow a logical order and avoid complex filtering. The respondents are more likely to answer truthfully without prompting from an interviewer. On the other hand, in an interviewer-administered questionnaire (e.g. face-to-face interview or telephone interview), the questions can be more complex as they can be clarified by the interviewers. However, the presence of an interviewer may “pressurise” the respondents to give “appropriate” rather than truthful answers.
WHAT IS A GOOD QUESTIONNAIRE?
A good questionnaire should be valid, reliable, clear, interesting and succinct.
Valid
A valid questionnaire should ask what it intends to ask, i.e. the questions should be phrased in such a way that the respondent understands the objective of the question. To achieve this, the questionnaire should be reviewed by the “content expert” during the pilot test (e.g. if the target respondent is a diabetic patient, then a diabetic patient should comment whether he understands the questionnaire). Any uncertainties and queries should be clarified till the question is clearly understood.
Reliable
A reliable questionnaire should yield the same answer if the same question is posed to the respondent repeatedly in a short span of time. This can be achieved by performing a “test-retest”, i.e. administer the same questionnaire to the respondent a second time and check for consistency of the answer. Any discrepancy in the answers could be due to lack of clarity of the questions and this should be reviewed and rephrased.
Interesting
An interesting questionnaire is more likely to be completed by the respondent and hence yields a better response rate. This requires the researcher to put some thoughts into asking questions that are relevant to the respondent and in a logical sequence.
Succinct
A succinct questionnaire asks questions that aim to answer only the research objectives. Any questions beyond the scope of the research should be excluded. It is common for researchers to “cast the net wider” so that they will collect more data, regardless of whether these data are important or not. This usually happens when the researcher has not properly thought through the research objectives. It runs the risk of asking too many questions and the questionnaire runs into many pages.
HOW TO DESIGN A GOOD QUESTIONNAIRE?
Developing a conceptual framework
The first step of designing of a good questionnaire is to construct a conceptual framework. The researcher needs to be very clear about his research questions and what “dependent” and “independent” factors he intends to investigate. Consider this research question: “What is the health-seeking behaviour of parents whose children have upper respiratory tract infection, and what are the associated factors?” I would develop a conceptual framework (Figure 1, Page 35) based on literature review, established theoretical framework and discussion with experts in that field. By creating the framework, the researcher can now ask questions regarding “parental health-seeking behaviour” (dependent variable) and associated factors e.g. education level, household income, age of child, etc. (independent variables). The importance of this framework is to ensure the research covers all relevant variables and any irrelevant variables can be