What inputs and outcomes might you evaluate here: How would an experienced secretary react after discovering a newly hired janitor was making more money than he/she was?
It seems we are meant to compare the motivation and overall happiness of the secretary before and after he/she made this discovery.
The input to consider is stated in the question. The input was finding out about the pay discrepancy. This is the independent variable in this question. The outputs would be a little harder to define. We would need to identify some way to measure the level of motivation of the secretary. The best way to do this would be to measure the quantity and quality of work that he/she did before and after the discovery. We would hypothesize that the quality and/or quantity of the work would decline after the discovery. This would be because the secretary would presumably be somewhat disgruntled on making this discovery.