The trick here is to be concise and accurate with your evidence but also be ready to reference. Don’t just state the fact itself (e.g. a study demonstrated this or X said this) but also know when and where this information was presented. Knowing that politician x said y in 2012 at location z adds another layer of depth to the presentation of your fact. It shows that it’s not just a ‘fact’ you heard from a friend, read in a tabloid or presumed to be true – it’s something you know indisputably and can prove to others by finding the information once again.
Being ready to reference who said your point and when they said it can also add to the strength of your sources. Statistics and evidence are easy to falsify and twist to a different interpretation and you can find many ‘facts’ from tabloids, trashy internet polls to support your points. Nonetheless, an intelligent and skeptical debater won’t trust or believe any facts presented from dubious sources – your natural intuition can tell you that a study performed at Harvard University by a leading researcher in his or her field is a better source of information than a Facebook survey.
When researching, it’s important to at least some evidence and facts for each of your main points. You may have dozens of different points you wish to bring up or contest in an argument, but you need to decide what handful of points you really want to drive home and make sure you can evidence and support them well with facts if necessary. Smaller points can support your main points with less need for factual support themselves; although if you are willing to put the time and effort into researching them this can make your argument even stronger.
Don’t mistake the term ‘research’ here as purely academic. Using studies and statements from researchers and experts can add validity to your argument, but often the evidence and facts we need are more mundane. For example, let’s re-imagine an argument concerning the household budget of a husband and wife. Suppose the husband wants to convince the wife that they need to have a stricter budget. The evidence required here won’t be found through some study or expert, but by having precise knowledge of bank statements to show just how much was spent, where it was spent and how to spend less.
Likewise, if you were trying to argue for yourself at a job interview, backing your points up with simple evidence is good too. If you wanted to prove that you were a hard worker, you could point to the fact that you won employee of the month at your last job or that you were favored for promotion, for example.
Now that you’ve clarified your argument and you have some facts to support your main points, you will be in a much stronger position to defend your opinion when the time arises. However, you can still go one step further by anticipating how a critic, skeptic or another person in the debate might attack your argument. If someone were to disagree with your argument, what would be the points they raise? What would they find contentious?