Randomized response surveys are an important part of the techniques used by survey statisticians. Survey methods have been developed for mapping the human genome and identifying the genes in a person's deoxyribonucleic acid (DNA). This opened the door to a new type of medical investigation. Some, like hemophilia, are clearly the result of inherited faulty genes. Others, like Alzheimer's disease, or cardiovascular disease, or breast cancer, are believed to be heavily influenced by faults in the DNA the patient inherited from his or her parents. Medical scientists began to assemble groups of patients with a given disease and compare the genes in their DNA to a similar group of healthy subjects. The respondent is given a randomizing device, which is used to decide what question to answer. The theoretical probability of an “yes” answer to the innocuous question is known, as is the probability of choosing it.