Final answer:
Polonius' plan in 'Hamlet' is to use Horatio to survey whether others in the kingdom believe in the presence of spirits, aiming to determine the validity of Hamlet's claims of seeing his father's ghost.
Step-by-step explanation:
In Shakespeare's Hamlet, Polonius' plan for testing his theory about Hamlet's behavior involves using Horatio to conduct a survey.
This plan is aimed at understanding whether the visions that Hamlet professes to see are believed by others in the kingdom.
The implication here is that Polonius is attempting to determine if Hamlet is truly mad or if there is some substance to his claims. Polonius is skeptical of Hamlet's report of seeing his father's ghost, and by employing scientific methods, like hypothesis testing, he hopes to reveal the truth.