What technique is makes holes or inserts and removes screws?

In which research method does a researcher change the value of one variable to determine how the change affects another variable? a. experiment b. observational research c. survey d. case study

What is affirmative action as a social program intended to accomplish? do you think it has been successful? what are some specific examples that you can offer to support your answer? this is for my multicultural studies class i need asap !

When pay is made public, people evaluate how equitable their pay is in light of the pay other people are receiving. the problem in this case is that dwight and guillermo have found out that others are getting paid more than they do for the same work. what are they likely to do under these circumstances