When a new drug is developed, we need to test how well it works. So, we hold clinical trials.
In these trials, patients can sign up to test the new drug. However, if everyone is given the same drug, it is impossible to compare and see how the new drug works.
So we divide the participants into two groups, one taking the new drug, one taking a similar-looking pill with no physiological effect. This way we can compare the different results of the two groups to see if the new drug helps. ... |