Random selection and assignment (true experimental designs require random assignment, but quasi-experiments do not)
Random selection involves drawing the sample from the population as a whole
Random assignment involves random assignment to experimental or control groups, where every participant has an equal opportunity to be selected
A blinding technique can be implemented to minimize bias. However, this may not always be feasible.
Single blinding – one party (either the participant or researcher is unaware of the assigned groups)
Double blinding – both the participant and researcher are unaware of which group is the experimental or control
Triple blinding – all parties, including the individuals analyzing the results are unaware of the treatment and control groups
2. Treatment and control groups
The only expected difference between the experimental and control group is the dependent variable that is being studied
There can me multiple experimental groups
3. Treatment manipulation
Independent and dependent variables. Researchers will manipulate the independent variable to see if this will affect the dependent variable
Provides the ability to determine the “cause” in the cause-effect relationship.
The use of pre-test and post-test measures will determine the validity of the research outcomes
(Bhattacherjee, 2012; Hariton & Locascio, 2018)
(UNICEF Innocenti, 2014)