No clue to be honest with ya buddy
Answer: universal myth of the descent of the hero (ego) to the underworld (unconscious) to search something. In Greek mythology who descends is: Heracles, Orpheus, Odysseus, Menelaos and many other. They do not always return. The same myth appears in other mythologies. In Mezopotamian myth it is for example the goddess Innana. Christ himself descended into the underworld only to be resurrected. Descend into the underworld makes part of mystery religions (Eleusine mysteries).
Explanation: it is an image, a metaphor of re-birth, re-newal. So-called "katabasis". The same image appears in dreams and fantasies as well. This motive is very often used in art works.
The experimental units are what you apply the treatments to. In this experiment it would be the subjects or the customers in this situation since they will be treatment (either standing at their regular height or squatting to meet the eye level which could affect the amount of tip they give). An example of randomization can be numbering each table in the restaurant and picking them out of a hat and going to that table that you randomly chose and imposing the treatment on the customers there. Because tips depend on the income of the customers and how much they are willing to give for their meal. If not even income some people are willing to give despite how much money they make so their tips may higher than the wealthy crowd. Other factors the experimenters may not be able to control is the mood of the customers as well isn't it more likely if someone is enjoying their time to give more to the server despite the service the waiter.
The culture of different countries. What may be common in one culture, such as waving in the United States, might be offensive in places like Greece, where putting all five fingers in the air is an offensive gesture.
