Here, a pharmaceutical company develops a new anti-hypertensive drug; samples of 24 hypertensive patients, randomly selected from a large population of hypertensive people, are randomly divided into 2 groups of 12, and one group is given the new drug over a period of 1 month & the other group is given a placebo according to the same schedule, Since a new drug (intervention) is given it is an experimental/ interventional study (not a prospective study which is only observational in design) Also, there are 2 groups, i.e. experimental group (Intervention – new drug is given) and reference group (no intervention is given – only placebo is given) which are compared concurrently, thus it is a ‘Concurrent parallel design of RCT’ (there is no cross-over) Also, neither the patients nor the treating physicians are aware of which patients are in which group, thus it is a ‘double blinded RCT’.