Researchers who study sensitive topics are often confronted with a higher refusal rate and often obtain more socially desirable answers. To tackle these problems, Stanley L. Warner introduced the randomized response technique (RRT). This is an interview method that guarantees total privacy and therefore, in theory, can overcome the reluctance of respondents to reveal sensitive or probably harmful information. Warner's original method used a randomization device (usually colored beads, coins, or dice) to direct respondents to answer one out of two statements, such as:

• A: I am a communist. (A: selected with probability p)
• B:I am not a communist. (not-A: selected with probability 1-p)

Without revealing to the interviewer which statement was selected by the dice, the respondent answers true or not true according to whether or not ...