Experimental

An impact evaluation design in which random assignment has been used to allocate the intervention amongst members of the eligible population. Also referred to as Randomized Control Trial (RCT). Since there should be no correlation between participant characteristics and the outcome, and differences in outcome between the treatment and control can be fully attributed to the intervention, i.e. there is no selection bias. However, RCTs may be subject to several types of bias and so need follow strict protocols.