Posts Tagged ‘sensitive questions’

Randomized Responses: More Indirect Techniques to Asking Sensitive Survey Questions

June 23, 2010

Yesterday’s post discussed approaches for asking survey questions of a sensitive nature in a way that would make individual respondents more inclined to answer them truthfully. Sometimes, however, you don’t care about the individual respondent’s answer to the sensitive question, but would rather get an idea of the incidence of that sensitive issue among all respondents. Sometimes, knowing the incidence of such a topic is what we need in order to conduct further research, or get an understanding of the market potential for a new product, or decide how to prioritize the allocation of resources for exploiting that instance. The most effective ways to do this are through Randomized Response Techniques, which are useful for assessing group behavior, as opposed to individual behavior.

Let’s assume that you are marketing a new over-the-counter ointment for athlete’s foot to college males, and you want to understand how large a market you have for your ointment. You decide to survey of 100 college males, randomly selected. Asking them if they’ve had athlete’s foot might be something they don’t want to answer, yet you’re not concerned with whether a particular respondent has athlete’s foot, but rather, get an estimate of how many college age men suffer from it.

Try a Coin Toss

One indirect way of finding out the incidence of athlete’s foot among college men might be to ask a question like this:

“Flip a coin (in private) and answer ‘yes’ if either the coin was a head or you’ve suffered from athlete’s foot in the last three months.”

If the respondent answers “yes” to the question, you will not know whether he did so because of the athlete’s foot or because of the coin toss. However, once you’ve compiled all the responses to this question, you can get a good estimate of the incidence of athlete’s foot among college males. You would figure it out as follows:

Total Respondents


Number answering “yes”


Expected Number of Heads on flip


Excess “Yes” over Expected


Percent with Athlete’s Foot (15/50)


Generally, when you flip a coin, you expect the results of the toss to come up “heads” about 50% of the time. If 65% of the respondents answer “yes” to the heads/athlete’s foot question, then you are 15 points over the expected value. Dividing that difference by the expected value (50) gives you an estimate that 30% of respondents have athlete’s foot.

Roll the Dice

Another approach would be asking respondents to roll a die and answer one question if the roll comes up anywhere from 1 to 4 and answer another if the roll comes up 5 or 6. If the die comes up as 1-4, the respondent answers the question, “I have had athlete’s foot” with either a “Yes” or a “No.” Respondents whose die roll came up 5 or 6 will need to answer the yes/no question, “I have never had athlete’s foot.”

What is the probability that a respondent has had athlete’s foot? The probability of a “Yes” is determined as follows:

P(YES) = P(Directed to first question)*P(Answering Yes to first question) + P(Directed to second question)*P(Answering Yes to second question)

Remember that respondents have a 100% probability of being assigned to either question. Hence the probability of being directed to the first question must be subtracted from 100 in order to get the probability of being directed to the second question. Expressing the probabilities in decimal form, we modify the probability equation as follows:

P(YES)= P(Directed to first question)*P(Answering Yes to first question) + (1-P(Directed to first question))*(1-P(Answering Yes to first question))

In the above example, the probability of being assigned the first question (for rolling a 1-4) is .67 (four chances out of six, or two-thirds). Now, if 35 respondents indicated “Yes” to “I have had athlete’s foot”, we get the following equation, denoting probability as “P”:

0.35 = 0.67P + 0.33(1-P)

0.35 = 0.67P + 0.33 – 0.33P

0.35-0.33 = 0.67P – 0.33P

0.02 = 0.34P


Hence, 5.88% of respondents will have had athlete’s foot.


There are several other randomized response techniques you can do, but these two are some examples you might want to try. Note that the dice approach may not be a very reliable estimator, since if 36 respondents indicated “Yes”, then the probability increases to 8.82%; it’s as if a 1% increase in “Yes” responses increases the overall probability of a “Yes” response by almost 3%. Randomized response techniques are good when you don’t care about the individual responses to sensitive information, but want to know the incidence of such behavior within the respondents. By wording questions in this fashion, you can put respondents as ease when asking these questions, and give them the feeling their responses are obscured, all the while gaining estimates of the percentage of the group engaging in said behavior.

Asking Sensitive Survey Questions

June 22, 2010

As marketers, sometimes we need to get information from respondents that they may not be willing to volunteer freely. When confronted with such inquiries, people may ignore the question, provide either untrue or incomplete responses, or even terminate the survey. Yet often, the survey often provides the only feasible means of obtaining information about a respondent’s religious affiliation, race, income, or other sensitive information. What’s a marketer to do? There are several ways around it:

Build Rapport with Respondent

Quite often, it is best to start a survey with neutral questions, and let the respondent work his or her way through the survey, letting each question lead up to the information you need to ask about. Placing controversial questions late in the questionnaire has two benefits. First, if the respondent chooses to stop the survey once he or she reaches the sensitive questions, you still have the respondent’s answers to all questions beforehand, which you can use for other analyses. Secondly, as the respondent works through the easy, unthreatening questions, he or she may feel as though trust is being established, and will be more likely to answer the question asking the sensitive information.

Be Casual About it!

Let’s assume you are trying to measure the incidence of tax cheating. Getting truthful responses can be very difficult. Try reducing the perceived importance of the topic by asking the question in a nonchalant manner: “Did you happen to have ever cheated on your taxes?” Worded this way, the question leads the respondent to believe the survey’s authors do not think that tax cheating is a big deal, so the respondent may be coaxed to answer truthfully.

Make it Sound Like “Everybody’s Doing It!”

Instead of directly asking a respondent if he or she cheats on his/her taxes, ask if they know of anyone who does. “Do you know any people who cheated on their taxes?” Then the next question could be, “How about you?” When he or she feels he/she isn’t alone, the respondent may be more inclined to be honest. Another way is to combine the casual approach with this one: “As you know, many people have been cheating on their taxes these days. Do you happen to have cheated on yours?”

Choose Longer Questions Instead of Shorter Ones

Longer questions can “soften the blow” with the excess verbiage, and reduce the threat. Consider these examples:

  1. “Even the most liberal people don’t pay their fair share of taxes to the government. Have you, yourself, not reported all your income to the government in the past two years?”
  2. “The Investors Business Daily recently reported on the widespread practice of middle class Americans to not report all their income for tax purposes. Have you happened to report less than all your income at tax time?”
  3. “Did things come up that kept you from reporting all your income to the IRS, or did you happen to report all your income?”

Note the patterns here. In the first question, we again make it sound like everyone is cheating on taxes. In the second, we appeal to an authority. In the third, we make it sound like circumstances beyond the respondent’s control made him or her unable to report all his income.

Try Some Projective Techniques

Make it sound like the respondent is just giving an estimate about someone else. Ask, “As your best guess, approximately what percentage of people in your community fail to report all their income at tax time?” When asked this way, a respondent might base the response on his or her own personal experience.

Try a Hierarchy of Sensitive Issues

Have a question that shows a list of answers ordered from least sensitive to most sensitive. A question like this:

“In the past 12 months or so, which of the following have you done? (Select all that apply):

    “Wear your shirt inside out”

     “Forget to hand in homework”

    “Lock your keys in the car while it was still running”

    “Discipline your child by spanking”

    “Take money out of your spouse’s wallet”

    “Meet an ex-girl/boyfriend behind your spouse’s back”

    “Withhold some information about your income at tax time”

    “Falsely accuse your neighbor of tax dodging”

Notice how this question moves the respondent from less threatening to very threatening answer choices. And by keeping the taxes part embedded – not the very first or the very last – the respondent sees that there are much worse behaviors than tax cheating he/she can admit to. Hence, the he/she is more likely to be truthful.


Questionnaire design is as much an art as it is a science, and wording sensitive questions is almost entirely an art. By building trust with your respondent, making him/her feel that it’s purely human to have the issue/behavior you’re trying to get the respondent to talk about, and finding soft, indirect ways to pierce the issue, you can get him or her to contribute more truthfully and calmly. As they say, “You attract more flies with honey than you do with vinegar!”