This is a form of data discovery. It allows a user to specify a cohort they are interested to find, such as ‘Females with Asthma’. The system can then inform the user which datasets contain individuals that meet their cohort definition. The approach does not reveal individual data but tells the user the scale of the cohort available (i.e. there are 100 people across five data sets that meet your definition). Another term for it is study feasibility.