This book provides a chronological, comprehensive, and up-to-date review of indirect methods of data collection from the human population such as randomized response, non-randomized response, item count, item sum, nominative, and negative questioning techniques. Such surveys include questionnaires on sensitive issues such as domestic violence, the history of induced abortion, involvement in fraud, plagiarism, affiliation with political parties, opinion of government policies, and religious practices, to name a few. The book also studies methods of drawing inferences from such data. The methods provided in the book can be applied to any complex survey design and a wide class of estimators. This book may serve as a handbook of indirect survey methodologies, as readers may receive a wide spectrum of materials from this book alone. Most of the randomized response (RR) techniques are described with the aid of diagrams so that readers can easily understand the randomization techniques, their applicability, and their complexity in real surveys. Applications of different indirect survey methodologies in various areas are presented.