How you ask survey questions can make or break your data, and if you’re asking questions about sensitive topics, how you ask becomes even more critical.


When answering questions about sensitive topics – such as sexual activity or drug use – people tend to give what they perceive to be a socially acceptable answer, instead of telling the whole truth. In a recent post, I taught you several ways to detect and avoid this “social desirability bias,” including validating your data against gold-standard benchmarks and asking your respondents to evaluate other people’s habits instead of their own. This week I have two additional strategies that you can employ. Both have benefits and costs, so thinking carefully about which is most appropriate for your research is important.


1. Guarantee Anonymity

The first approach is reassuring respondents that their data will be completely anonymous. Prior research has indicated that respondents are more willing to share sensitive information if they know the data can never be linked with their personal information. However, recent research has also demonstrated that complete anonymity may come at the cost of data quality.


2. Use a Control

A second, commonly used approach is the “Item-Count Technique.” In this approach, the researcher creates two lists of items. The first is the control list, which contains completely innocuous things that should not be sensitive to anyone:


Asking about sensitive topics


The second list contains everything on the first list plus one sensitive item:


Sensitive Survey Questions


Respondents are then randomly assigned to see one of the lists. To determine the prevalence of the sensitive item the researcher finds the difference in the mean number of items reported between the two lists. The difference is attributed to the sensitive item.


The downside of this approach is that you only get estimates of the sensitive item in the aggregate population of your respondents, not at the individual respondent level.


For any of these strategies, it is important to put yourself in your respondents’ shoes and consider that they might not enjoy answering uncomfortable or complex questions. Whichever strategy you decide to employ when asking about sensitive items, it is generally best to avoid asking any more sensitive questions than absolutely necessary.