These designs are generally used to determine cause and effect. They allow us to make inferences. It is considered to be quantitative, because the results are organized and presented systematically, usually in the form of statistics.
Interventional research is, quite simply, research where it is possible to intervene in treatment.
The KEY difference between experimental designs and quasi-experimental designs is randomization. This will be discussed more fully under experimental designs. Experiments 101 is dedicated to helping a beginner with his or her first controlled experiment. It is particularly intended to help with experiments with human subjects, as occur in the study of human computer interaction or software engineering. However, the material should be applicable to a wider audience.