AQA Psychology – Research Methods Practice Test

The key idea is that quasi-experiments study cause-and-effect without random assignment of participants to groups. In these designs, the independent variable isn’t allocated by the researcher in a random way, often because it’s a pre-existing or naturally occurring condition rather than something the researcher can assign. That’s why the description that the independent variable has not been determined by anyone and the variables simply exist fits best: it captures the lack of random assignment or full experimental control over how groups are formed. If the IV were randomly assigned, you’d be looking at a true experiment. The requirement for ethical approval is separate and not what defines a quasi-experiment, and an IV that is clearly manipulated by the researcher with randomization missing is still characterized by the lack of random assignment rather than by the existence of the variable itself.