Some designs for clinical trial research, such as drug effectiveness research, allow for modification and make use of an adaptive design. Designs such as adaptive group-sequential design, n-adjustable design, adaptive seamless phase II–III design, drop-the-loser design, adaptive randomization design, adaptive dose-escalation design, adaptive treatment-switching design, and adaptive-hypothesis design are adaptive designs.

In conducting clinical trials, investigators first formulate the research question (objectives) and then plan an adequate and well-controlled study that meets the objectives of interest. Usually, the objective is to assess or compare the effect of one or more drugs on some response. Important steps involved in the process are study design, method of analysis, selection of subjects, assignment of subjects to drugs, assessment of response, and assessment of effect in terms of hypothesis testing. ...