How do I make a convincing argument in an essay?
There are a great many ways, but I generally fall back to the classic logos, pathos, and ethos from your friend and mine, Aristotle. Basically, the point of this ancient Greek fellow what that humans are generally persuaded by three basic things. Logos, or logic, is an argument based on provable and defensible facts. Things that no one can really argue with. Pathos, or an emotional appeal, is based on manipulating peoples emotions. Ethos, or ethics, is rooted in values and the notion of right and wrong. The key to using any of these three approach is knowing your audience. Are they an emotional bunch? Or are they more logical?
Why is the lighting so strange in old horror movies? What were they trying to do?
Generally speaking, when light is shone on the face from below it creates an unnatural feeling on an almost subconscious level. Not only do lights rarely come from below in day to day life, but the shadows of facial features creates a distorting effect.
What exactly is a communication theory, and why is it useful?
A theory -be it scientific or in the social sciences - does two fundamental things: it describes and explains. So, when you look at this in the context of communication, you can start to see how it would be useful. Let's say you see two people arguing in a store. There are a lot of things to observe here. Whats said, body language, what the people are wearing, etc. When you pick one of those aspects of what is going on and try to understand what is happening based on that, then you are using a theory. Now, communication theorist are big fans of giving their theories elaborate names (mostly cause it sounds cool), but a theory like 'kinesthetic theory' looks at body language to determine what messages are really being sent in the argument that we were just talking about. Is one person saying "I'm sorry" while at the same time folding their arms and snarling? This would be an example of a mixed message if you are considering kinesthetic theory. In short, a theory describes and explains, but it is also like a lens through which you can look at a situation.