Final answer:
Tests of controls in auditing assess the effectiveness of a company's internal controls, and they generally do not address the cost effectiveness of these controls. The main purpose is to ensure that the controls are consistently applied and executed as intended.
Step-by-step explanation:
Tests of controls in an auditing context assess the processes and safeguards a company has in place to ensure the reliability of its financial reporting. Specifically, these tests determine whether the controls are applied consistently, who applied them, and in what manner. However, when addressing what tests of controls do not ordinarily tackle, the correct option is D. The cost effectiveness of the way a control was applied. This is because the primary focus of these tests is the effectiveness of the control, not the cost associated with implementing or maintaining the control.
Effective controls are crucial in ensuring valid and reliable data, which in turn, facilitates the comparison between groups where ideally, only one independent variable differs. This emphasizes the control group's importance in experimental design as it should mirror the test group in all but the variable being tested. It's this rigidity and control that allows for the accurate attribution of any differences in outcomes to the independent variable in question.