This is an example of convergence evidence.
Convergence evidence refers to the type of evidence that derives from independent sources that couldn't be objectively measured by the researcher.
In the case above, the data about the satisfaction came from the subject's personal evaluation and experiences
A slave's monologue could be:
The democracy is highly undemocratic. Me and my family are treated as property and have no rights. They sell us, separate us, or harshly punish us all the time and we are not considered to be citizens. If something bad happens, a regular citizen would get a fine while we get physically punished through means of flogging. If we see a crime our testimonies are not accepted except when we are tortured for information.
I believe the answer is: Public speaking
There are three major purpose for someone to conduct a public speaking. The first one is to inform the audience, the second purpose is to persuade the audiences to do something, and the third purpose public speaking is to entertain the audiences.