Mapping an argument's structure means to figure out, at minimum, the claim, reasons, and evidence that make it up and to identify the logical connections between those things.
Why do that? Well, we can't evaluate the strength of an argument unless we know what the argument actually is. And writers, for better or worse, seldom lay it all out for readers as an outline, with the claim clearly stated, the reasons listed in order of importance, and the evidence neatly stacked up in rows. Instead, those things tend to be somewhat hidden among the assortment of sentences, paragraphs, and sections that make up a piece of persuasive writing.
College-level readers are expected to be able to see through the jumble of ideas in any given text, however, and to parse out the underlying logical structure—first to comprehend clearly what a text is saying, and then often to analyze or evaluate how well it is saying it.
This article is meant to give you some tips and techniques to achieve that goal of comprehension. By mapping an argument's structure, you can have a high degree of confidence that you know what a text is saying, so you'll be able to, for example, participate in a class discussion, respond to that text in a piece of your own writing, evaluate the strength of its argument, or synthesize it with other sources—whatever you may need to do with it, in other words.
In the following sections, I lay out a 4-step process that I typically use to map an argument. This isn't the only way to do it, but I find this approach gives me consistent results with the least amount of effort.
Step 1: Identify the Claim
The first step in mapping an argument's structure to is identify its main claim. The claim is the thing the author is trying to convince the reader of—we often call this the thesis, the main idea, or the conclusion.
In Research and Evidence, we talked about how a claim is, by its very nature, a statement with which a reasonable person can disagree, something about which persuasion is therefore possible. Claims tend not to be statements of fact (which are generally either true or false); they tend to be statements of opinion or preference and often are or can be phrased as a should-statement.
How do we identify the claim/thesis/conclusion? Well that's what PTIC analysis is all about. If you haven't yet read it (or need a refresher), I recommend you check out Getting to the Point with PTIC. I don't know of any better technique to more quickly and accurately discover an argument's main claim.
Step 2: Identify the Evidence
You might expect the next step to be to identify the reasons—after all, an argument's claim is, in turn, directly supported by reasons, as we discussed in Research and Evidence.
However, in practice, spotting the reasons in an argument tends to be the hardest part, because they so often go unsaid or only partially stated. It's actually much easier to instead proceed by identifying the evidence that is used to support to the reasons.
There are many types of evidence, but most of it tends to be easily recognizable because it consists of facts, figures, statistics, quotations, examples, and other pretty concrete things.° Evidence tends to describe the way the world is (as opposed to the way the writer thinks it should be, which is more of what a claim or reason does).
You may find it helpful to review the various kinds of evidence as described in detail in Research and Evidence. It presented the following categories and types:
Evidence from Yourself
- Personal experience
- Personal observation
Evidence from Others
- Testimonial
- Expert opinion
Evidence from the World
- Case example
- Research study
Evidence from Logic
- Thought experiments
- Hypothetical situations
- Syllogisms
- Analogy
When I say "identify the evidence," I mean it literally. The technique I find most useful is to highlight or mark every sentence or passage that presents a piece of evidence. I use different colors or other markings to keep the various pieces of evidence separate also.
Step 3: Identify the Reasons
In most arguments, a claim is supported by one or more reasons. These reasons are usually also debatable statements (so we could call them sub-claims), and they too need support—that's what the evidence is for. In other words, the claim is supported by reasons, which are in turn supported by evidence. That's how an argument is structured.
Since we've already identified the claim and the evidence, our task now is simple: figure out what connects the two. Those will be our reasons. A reason can usually be appended to the claim with the word because:
You should read To Kill a Mockingbird because it is a great book.
Similarly, a phrase like as evidenced by can usually attach a piece of evidence to the reason it is meant to support:
That To Kill a Mockingbird is a great book is evidenced by the fact that it won a Pulitzer Prize.
So to find and articulate the reasons in an argument you are mapping, you need to find the concepts that logically connect claims to evidence.
Sometimes the reasons will be stated outright, though you may not have noticed them as reasons on your first read. If you marked all the evidence in Step 2, you can go back now and look at everything you didn't mark—do any of these passages reveal reasons?
Writers tend to state their reasons at the beginnings and ends of paragraphs and sections, as they are setting up the evidence or as they are transitioning between ideas. So it can be smart to reread those areas of the argument in search of reasons. Additionally, writers will sometimes state their reasons as part of their thesis statement,° as in this example:
Apples are the greatest fruit in the world because they are the most nutritious, most delicious, and most affordable fruit around.
Pay attention to any signposts the writing may exhibit. For example, if an argument is divided into sections, those sections might each tackle a single reason. If the sections have headings, those headings might be clues about what the reasons are.
If you can't find a reason, or if the reasons really are unstated, you may have to intuit what they are. One way to do this is to go through the evidence piece by piece and, for each one, ask yourself "What is this evidence meant to prove?"
Warning: Arguments Can Be Complex!
Up to now I've made it seem like every sentence in an argument will be a claim, a reason, or evidence. But in real life, arguments can be quite a bit more simple or complex than that.
On the simple side, really basic arguments may forgo having supporting reasons and instead just link the claim directly to some supporting evidence:
Let's order pizza tonight—I've got a 50% off coupon!
On the complex side, there could be layers of reasons between the claim and the evidence. For longer or more developed arguments, it's typical for a writer to support the main claim with a couple of big, overarching reasons, which are then supported by their own sub-reasons, which are then supported by evidence.
Additionally, arguments regularly contain content that isn't claims, reasons, or evidence at all. Some examples:
- Hooks: Many arguments start with a hook, something to draw the reader in and keep them reading. A hook could be an interesting quote, statistic, or anecdote, for example. While these all look like evidence, it might not really support a reason and be part of the main argument structure.
- Context/Background: Sometimes an author needs to provide information to contextualize their argument or to make sure their readers know the history of an issue or the definitions of some key terms.
- Establishing Ethos: Ethos refers to the author's credibility with the audience. Because an audience is unlikely to be persuaded by an argument made by someone they don't trust, the author may provide background information about themselves in order to establish that they are knowledgable, trustworthy, or fair.
- Counterarguments: Good writers acknowledge that issues have multiple sides, and they might spend time describing what their opponents have to say about the issue (by doing this fairly, they also enhance their credibility). Obviously such counter-claims, counter-reasons, or counter-evidence aren't part of the main argument.
- Rebuttals: After bringing up a counterargument, a writer may rebut it—that is, they may argue that the counterargument is flawed or outweighed by other considerations.
While it can be tempting to want every line of an argument to be clearly identified as either a claim, a reason, or evidence, in practice this is seldom possible, so allow some leeway as you are mapping.
Step 4: Represent the Argument Visually
Once you are satisfied you've figured out the claims, reasons, and evidence (and other things) that make up the argument, the last step is to represent that argument visually in some way. You might want to write all over a copy of the argument itself, representing the argument with lines and annotations. You may prefer to work on a separate document, creating an outline or a bubble chart or something in between. Whatever method you like is generally okay (unless your teacher is asking for something specific, of course).
If I'm being honest, I always start this step earlier in the process. I start making a rough visual as I'm identifying the evidence and reasons, because the act of trying to organize things visually is a key part of my thinking process. When I can see the claim and the top of a piece of paper and all the evidences listed at the bottom, it helps my brain start to intuit what reasons might connect them all.
Inevitably I get it all wrong on my first try, and my first map ends up half scratched out, the lines redirected along new paths. That's why I usually make a fresh new map for Step 4, one that builds on all the thinking that went before and is a closer representation of how the argument is structured.
Summing Up
Let me be clear about two things.
One, mapping out an argument is hard. It is a challenging exercise and demands a significant amount of cognitive energy to do well, even for relatively short arguments, such as what you find in newspaper editorials. It takes practice to do well, and (if my own experience is any guide) it never becomes what I would call "easy."
Two, there are no absolutely correct answers. Two people can map an argument in significantly different ways that are both defensibly accurate. I don't mean that one will think the writer is for something and another that they are against that same thing. I mean that how readers name and group the reasons and evidences can vary somewhat within reason.
Being absolutely correct is not the point, anyway. The point of mapping isn't to say "This is what it is, no question" but instead to ensure that you understand an argument in as deep and granular a way as possible. It's to help develop your ability as an active reader so that you can be successful in college and beyond.
