Question

Why do some investigations require a control?

Answer 1

To be able to compare the results to a sample without any of the independent variable added.

Answer 2

Some investigation require control such that they can be able to compare results to a sample even without any of the independent variable which is being added.

Investigation is the act of investigating someone or something. Investigation can work for private investigator. There are different types of investigation. For example, Griffin investigation, Criminal investigation department, Federal Bureau of investigation.