Man-Lai Tang & Guo-Liang Tian 
Incomplete Categorical Data Design [PDF ebook] 
Non-Randomized Response Techniques for Sensitive Questions in Surveys

Respondents to survey questions involving sensitive information, such as sexual behavior, illegal drug usage, tax evasion, and income, may refuse to answer the questions or provide untruthful answers to protect their privacy. This creates a challenge in drawing valid inferences from potentially inaccurate data. Addressing this difficulty, non-rando