I heard that Randomised Control Trial (RCT) is useful in examining the effectiveness of an intervention. Could you please introduce a bit more about it?

Glad to know.

Your reply helps me a lot! Many thanks!

Thank you for the great question. RCT originally was used in drug trials but now increasingly used in human services. It involves randomly allocating some participants to a group that receives an intervention and others to a group that doesn't receive it (known as the "intervention" and "control/comparison" groups). The purpose of randomization is to attribute outcomes to the intervention instead of any other factors influencing those outcomes to avoid bias.