During their speeches, the members of each side will be responsible for giving arguments in favour or against the motion as defined by the governement. They will also have to respond to each others' arguments; this is known as rebuttal or refutation. Argumentation is the real meat of debating. But 'argument' doesn't mean yelling at your girlfriend or your parents. An argument in debating is something very specific, to be defined in opposition to case, assumption, assertion and evidence. To look at it one way, your case is a statement that you have to prove is true. If you can prove that it's true, you win the debate. If as opposition you can prove that it isn't true, then you win the debate. But you don't just stand up and ramble on for 7 minutes about how you think you're right and the other guys are wrong. There has to be some structure to how you explain your point of view. Arguments are the backbone of that structure. An argument is a statement put forward by you which, if it is true, supports the truth or validity of your side of the motion. For example, if we take my earlier case about intervening in the Sudan. Let's say I define the case as a Chapter VII intervention by the United Nations: in other words, an invasion. Once I have laid out my case, I have to convince you that I'm right. So I will tell you that a) Sudan cannot escape this conflict on its own and too many people are dying, and b) that the UN has a moral responsibility to intervene and c) that the UN has a legal responsibility to intervene. Each of those constitutes an argument. But it's not enough just to say those things; I have to explain why they too are true. In a way, an argument is a mini-case. So to make it even clearer, debaters usually break down arguments into their three component parts: point, argument, evidence. The point is merely the statement itself. It is over very quickly. The argument is the reasoning that supports the statement. So let's take argument b) as an example. Here I would tell you that the UN is founded on the principles of human rights and human dignity, and that, as the most universal world organization and the corner-stone of world order, it represents all of humanity. I would then tell you that the Sudanese governement is massacring its own citizens along racial and ethnic lines for the benefit of a particular ethnic group, that humanity (and thus the UN) cannot tolerate this kind of behaviour as it is offensive to all, and that this is precisely the sort of thing the UN was founded to stop ( i.e. Nazi extermination of the Jews). The evidence is the examples that back up your reasoning, to show that it has some basis in reality. So, as evidence, I would give you examples of other situations where the UN has got involved for precisely the same reasons, such as Kosovo, the Congo, Sierra Leone, the former Yugoslavia, and Rwanda. This is an over-simplified version of course. But this process must be repeated for every argument. Most people will tell you that a CP case should have at least 4 arguments, and no more than 5. But this is only a guideline. Many of my own cases only have 3 main arguments. But these will be very large, complex arguments with many layers of reasoning and evidence, and this comes from years of practice. So until you have more experience, you should always aim to have 5 arguments for your cases.
Assertions and Assumptions vs. Arguments
One of the most common accusations that your opponents will throw at you is that you are merely asserting something rather than arguing it. The difference between the two is fairly easy to understand. Imagine that, instead of going through the steps of point, argument, evidence, I merely stated my point and left it at that. That is called an assertion: when one simply asserts the truth of a statement, without bothering to provide evidence of its truth. It is inevitable that at some point, some things will be assertions, because you are limited in the time you have to support your arguments and your means of providing evidence. I can tell you that the UN was founded to prevent crimes against humanity; but chances are I won't have a copy of the UN Charter around to show you that it's true. In any case, it is common enough knowledge that most people will believe me without me having to cite the specific articles in the Charter that make my assertion true. So, sometimes asserting is ok; don't think you have to prove every single little thing you say in a debate. But as a rule you should avoid making assertions as much as possible, especially when it comes to those things that are essential to your case. An assumption is just a hidden assertion. Sometimes it is hidden on purpose, and sometimes only because you weren't aware you were making the assumption when you made your argument. If we return to my case about UN intervention in Sudan, there is a perfect example of this. All of the arguments I put forth and explain deal with why the UN needs to and should intervene in Sudan. But nowhere do I explain that it can. I am assuming, that is to say, I am secretly asserting, that the UN will be able to find the resources and personnel to undertake this mission successfully. Every single case, and every single argument, no matter how good a debater the person who built it is, will be full of assertions and assumptions. So the best advice I can give a new debater is: look for the assumptions. That is your best and simplest strategy for undermining your opponents' logic. (Erik Eastaugh, Debates, Cases, Arguments, Evidence and Assertions-- the Jargon Explained)