challenges or operational risks necessary to finalize the trial protocol completely. These information gaps can result in multiple protocol changes before and after trial start-up, leading to the need for additional time and expenses that may prevent study completion. Further, the suitability and feasibility of new trial designs, which minimize infrastructure and reduce costs may need to be tested in the context of a particular intervention, at-risk group, symptom or venue. Preparatory studies may fill information gaps and address unknowns, improving trial design and knowledge of trial feasibility and thus saving NCI time and money.