Question

Give three (3) examples of experimental or observational studies that used (or might use) random sampling.

How might the outcome have been different for each had random sampling not been used? Explain.

Answer 1

1) Example of experimental study.

Suppose we want to study the different level of a particular food on the milk produced by the cows.

Here we need to assign the cows randomly. If we do not use randomization then the personnel bias may include in the study.

2)  Example of experimental study.

Suppose we take a group of adults and randomly divided them into two groups.

One group was told to drink tea every night for a week, while the other group was told not to drink tea

that week. Researchers then compared when each group fell asleep.

If the division of groups is not random then other factors which are responsible the sleeping hours of individuals introduced bias in the study.

3 )  Example of experimental study.

Suppose we want to examine defectives found in a box of 100 items.

This is called a observational study.

We need to select a box randomly from the available boxes. If we select box directly then the bias may introduced. For example if we select such box which is make at the time of starting of production which may include more difectives because the process may not work smoothly at that time.