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.
Types of experiments. By definition, all experiments involve manipulation of one or more independent variables, and observing the effect on some outcome (dependent variable). Experiments can be done in the field or in a laboratory. They can involve human or animal subjects.