This presentation will introduce the essential concepts of responsive and adaptive survey design, which are state-of-the-art survey design techniques for increasing the efficiency of data collection. After introducing the basic concepts of responsive survey design (RSD) and adaptive survey design (ASD), several case studies will be presented, illustrating how the use of these techniques has increased the efficiency (in terms of cost and quality of estimates) for studies employing a variety of data collection modes. Examples will range from major national studies to small local studies.