• Clinical research informatics entails all manner of activities but often focuses on retrospective historical studies and prospective clinical trials. Clinical research informatics pursues the development of methods and tools that support clinical researchers, whether that is reusing previously collected data or collecting new data in studies of their own. Clinical research informaticians seek to improve not only data collection but also the entire research process, from hypothesis generation, through study design and approval, to study execution and finally the analysis of study data. Clinical data repositories and clinical trials data management systems are major areas of focus in clinical research informatics.