Adaptive design is a research approach that allows for modifications to be made to a study during its course, based on the data that is gathered during the study. This method allows researchers to adjust the study design, sample size, interventions, or other elements in order to improve the study's outcomes or to better meet its goals. Adaptive design is often used in clinical trials and other research studies where the initial study design may need to be refined based on emerging results or unexpected findings. This flexible approach can help to improve the efficiency and effectiveness of research studies by allowing for real-time adjustments to be made.