Different Types Of Evidence In Writing

Evidence is the information that helps in the formation of a conclusion or judgment. Whether you know it or not, you provide evidence in most of your conversations – they're all the things you say to try and support your claims. For example, when you leave a movie theater, turn to your friend, and say "That movie was awesome! Did you see those fight scenes?! Unreal!", you have just made a claim and backed it up.

Most people think of "evidence" as numbers and quotes from famous people. While those are valid types of evidence, there are more to choose from than just statistics and quotes, though. There are four types, to be exact:

Statistical Evidence
Testimonial Evidence
Anecdotal Evidence
Analogical Evidence

1. Statistical Evidence

Statistical evidence is the kind of data people tend to look for first when trying to prove a point. That's not surprising when you consider how prevalent it is in today's society. Remember those McDonald's signs that said "Over 1 billion served"? How about those Trident chewing gum commercials that say "4 out of 5 dentists recommend chewing sugarless gum"? Every time you use numbers to support a main point, you're relying on statistical evidence to carry your argument.

2. Testimonial Evidence

Testimonial evidence is another type of evidence that is commonly turned to by people trying to prove a point. Commercials that use spokespersons to testify about the quality of a company's product, lawyers who rely on eye-witness accounts to win a case, and students who quote an authority in their essays are all using testimonial evidence.

3. Anecdotal Evidence

Often dismissed as untrustworthy and meaningless, anecdotal evidence is one of the more underutilized types of evidence. Anecdotal evidence is evidence that is based on a person's observations of the world. It can actually be very useful for disproving generalizations because all you need is one example that contradicts a claim.

Be careful when using this type of evidence to try and support your claims. One example of a non-native English speaker who has perfect grammar does NOT prove that ALL non-native English speakers have perfect grammar. All the anecdote can do is disprove the claim that all immigrants who are non-native English speakers have terrible grammar.

You CAN use this type of evidence to support claims, though, if you use it in conjunction with other types of evidence. Personal observations can serve as wonderful examples to introduce a topic and build it up – just make sure you include statistical evidence so the reader of your paper doesn't question whether your examples are just isolated incidents.

4. Analogical Evidence

The last type of evidence is called analogical evidence. It is also underutilized, but this time for a reason. Analogies are mainly useful when dealing with a topic that is under-researched. If you are on the cutting edge of an issue, you're the person breaking new ground. When you don't have statistics to refer to or other authorities on the matter to quote, you have to get your evidence from somewhere. Analogical evidence steps in to save the day.

Take the following example: You work for a company that is considering turning some land into a theme park. On that land there happens to be a river that your bosses think would make a great white-water rafting ride. They've called on you to assess whether or not that ride would be a good idea.

Since the land in question is as yet undeveloped, you have no casualty reports or statistics to refer to. In this case, you can look to other rivers with the same general shape to them, altitude, etc. and see if any white-water rafting casualties have occurred on those rivers. Although the rivers are different, the similarities between them should be strong enough to give credibility to your research. Realtors use the same type of analogical evidence when determining the value of a home.

When you use analogies to support your claims, always remember their power.

Photo credit: Billaday