[MUSIC] Today we are going to talk about the different types of experimental designs which market researchers undertake. The first type of experimental design is called pre-experimental design. So, under pre-experimental design, the market researchers usually do not have any control over who will be the test subjects. And when they are exposed to the experimental stimuli. So basically, the entire process is not in the control of the market researcher. Further, the market researcher has no control over who are going to be measured for the eventual outcome. And when they are going to be measured. So basically what we see here is you do not have any control over the subjects. About their measurements on the outcome, as well as when and who are going to be exposed to that treatment. Given this constraint, there's no possibility of randomization across the subjects or matching across the subjects. So, what is randomization? Randomization is assigning subjects to different groups randomly. And matching is basically assigning subjects to different groups. Such that they are homogeneous within groups and heterogeneous between groups. So essentially under pre-experimental designs, the market researcher cannot do either randomization or matching. The second type of market research is called true experimental design. Here, this is completely opposite to the pre-experimental design. Here the market researcher has total control over who will be exposed to the marketing or experimental stimuli. And also when they will be exposed to this stimuli. Finally, this experimental research allows control over who are going to be measured for the eventual outcome. And when they are going to be measured. So as you can see very clearly a true experimental design is a complete opposite of a pre-experimental design. Here of course, there is a possibility of randomly assigning subjects to different groups, as well as matching subjects. However, there is no possibility of self-selection. Finally, what you see here, the third type of experimental research is called quasi-experimental design. In this case, like pre-experimental designs, the market researcher has no control over who will be the test subjects. And when they are going to be exposed to the experimental stimuli. However, they do have control over when the potential subjects are going to be measured, and who are going to be measured. So as you can see, a quasi-experimental design is somewhere between a pre-experimental design and a true experimental design. In the next videos, we are going to look at certain statistical designs of experiments. Which are more technical and help marketers run test marketing studies with their potential consumer base. Thank you. [MUSIC]