Mapping an Argument: Thesis, Claims, Evidence and the Ideas in Graphics

Hook: the two-minute summary

Your friend missed class and asks what the reading was about. If you say It was about cooking, you named a topic. If you say It argued every student should take a cooking course because it builds independence, saves money and connects people, you named a thesis and its main claims. That second answer proves you understood. This lesson is about finding the most important ideas and the details that support them in persuasive and informational texts, and showing the relationships between them on a map.

The parts of an argument

• Topic: what the text is about (cooking classes).
• Thesis: the writer's main point about the topic, usually one sentence (every Ontario student should take a cooking course). In an essay it is often at the end of the introduction. Sometimes it is implied: you have to state it yourself.
• Claims (or main ideas): the reasons that support the thesis. In a well-built essay, each body paragraph has one, often in its topic sentence.
• Evidence (supporting details): what proves each claim.
• Counterargument and rebuttal: an opposing view and the writer's answer to it.

Kinds of evidence

Naming the kind of evidence helps you judge how strong it is.

A persuasive essay to map

Bring Back the Kitchen

(A persuasive essay written for this website.)

The first night in my cousin's university apartment, supper was a bowl of cereal. So was the second night. He could solve a quadratic equation in his sleep, but he could not cook an egg. Every Ontario high school student should take at least one half-credit course in cooking before graduating.

Cooking builds independence. Within a few years of graduation, most of us will feed ourselves. A student who can plan a week of meals, read a recipe and use a knife safely is ready for that day. A student who cannot is at the mercy of whatever is quick and packaged.

Cooking saves money and supports health. A pot of chili made at home feeds four people for roughly what one takeout meal costs. When you cook, you also decide how much salt, sugar and fat go into your food, instead of leaving that choice to a restaurant.

Cooking connects people. Food carries culture. A class could share family recipes, plan a potluck for the whole school, or invite a community member to lead a bannock workshop. Learning to cook is also learning about the people around you.

Some will say the timetable is already full. It is. But a cooking course could be one of the choices that already count toward a diploma, sitting beside the electives students choose now. No student would lose anything except the cereal-for-supper years.

Our schools prepare us for exams. They should also prepare us for Tuesday night.

Mind map or concept map?

• A mind map puts one idea in the centre and branches out with related ideas. It is fast and good for brainstorming or for showing relationships among characters or topics.
• A concept map also labels the connections: arrows carry words such as causes, supports, contradicts, is an example of. It is better for arguments, because an argument is a set of relationships.

How graphics carry important ideas

In articles and reports, some of the most important information is in the graphics: charts, tables, maps and diagrams. A good graphic does not just decorate the article. It can:

• compress many numbers into one picture you understand at a glance;
• show a relationship (bigger, smaller, rising, falling) that sentences explain slowly;
• state the main idea in its title.

When you summarize an article, the main idea of a graphic belongs in the summary.