Survey Question Tip #4 - Avoid Ambiguity

Writing a good survey question is not as easy as it seems. Use the wrong word or ask the question in the wrong way and you can negatively impact the quality and value of the data you collect. This post is the fourth in a series that will offer tips on how to write effective survey questions. 

​Tip #4:  Avoid Ambiguity
When writing survey questions, it is important to be as clear and specific as possible. Questions that are vague or ambiguous can confuse respondents and lead to inconsistent responses. Let's look at a couple of examples:

Let's say you work for a nutrition education organization whose aim is to ensure that city residents have access to nutritious food. You develop a survey that will measure individuals' nutritional behaviors. Two questions on the survey read as follows:

1. Do you eat breakfast regularly?
(Yes)
​(No)   

2. How often do you go to the store?
(a)  Never                                                                                                  
(b)  Once                                                                                                     
(c)  Once a week                                                                                      
(d)  Once every two weeks                                                                    
(e)  A few days a week, every week (two or three days a week)   
(f)  Every day                                                                                              


​Question 1 is ambiguous because the word 'regularly' can be interpreted in many different ways. To some, it may mean 'every day,' while to others, it may mean 'twice a week.' Avoid imprecise words (e.g., often, rarely, regularly, occasionally, sometimes, usually) when writing survey questions. A better question would be: 
​
1. About how many days in a 7-day week do you eat breakfast?
(a) I do not eat breakfast (or Never)    
(b) 1 to 3 days a week                               
(c) 4 to 6 days a week                              
(d) Every day (or 7 days a week)            

or even:

1. On average, how many days in a 7-day week do you eat breakfast?
​Please indicate a number between 1 and 7 ________
​
​Question 2 is vague because it does not provide enough context (i.e., a setting or time frame) for the respondent to interpret the question and select a response. What exactly are you asking? How often they frequent a store? How often they go to the store to buy groceries? Be specific! When writing survey questions, it is important to be as descriptive and precise as possible. It is equally important to provide respondents with a time frame (if applicable). Specifying a time frame (e.g., yesterday, today, in the last week) provides respondents with information about how the question should be answered. It also leaves little room for misinterpretation and improves the quality and accuracy of the responses. A more precise question would be:
​
2. In the last 30 days, about how often did you go to the store to buy groceries?
(a) Never (or I have not bought groceries in the last 30 days )    
(b) Once                                                                                                     
(c) Once a week                                                                                       
(d) Once every two weeks                                                                     
(e) A few days a week, every week (two or three days a week)   
(f) Every day​                                                                                            

Keep these three key questions in mind when trying to determine whether a survey question is ambiguous or not:

1. Do any of the words have multiple or misleading meanings?

2. Does the question text provide enough context so that all respondents can answer the question accurately?

3. Is the language used direct and specific?