Final answer:
Marlene learned to organize her desk through negative reinforcement, a process where the removal of an adverse event strengthens a desired behavior.
Step-by-step explanation:
Marlene learned to organize and straighten her desk through negative reinforcement. This operant conditioning procedure involves the removal of an adverse stimulus to increase a desired behavior. In Marlene's case, the adverse stimuli of not finding important papers and suffering the consequences was removed when she organized her desk, thereby reinforcing the behavior of organization. Negative reinforcement strengthens a behavior because the removal of an unfavorable outcome encourages the behavior to be repeated in the future.