Note: If more than $13,000 of debt is canceled in one year, the gift giver has to file a gift tax return (although they almost certainly will not owe a tax). That should not affect you as the recipient. Example: Roxy borrowed $6,000 from her dad while she was unemployed. She wrote up a promissory note for the debt.
Control Group and Experimental Group. True experiments must have a control group, which is a group of research participants that resemble the experimental group but do not receive the experimental treatment. The control group provides a reliable baseline data to which you can compare the experimental results.
In this type, as the name implies, there is the greatest amount of control. There are at least two groups used in this type of scientific experiment. Each group is made up of subjects that resemble each other as close as possible, such as by age, gender, etc.