Assumptions of a Well-Designed RCT
Careful design
High internal validity ensures unbiased causal inference
Random assignment decreases bias
A correct statistical test has been chosen for statistical conclusion validity
Sample size needs to be large enough to demonstrate treatment effectiveness
Ensures construct validity by choosing appropriate control conditions.
External validity: the obtained sample needs to represent the target attributes of the study and be applicable to other contexts
(Wadha & Cook, 2019)