How to Compare Arguments in Debate: Weighing, Impact and Clash
Comparing arguments, often called weighing, means showing why your argument matters more than the opposing one when both are partly true. This guide explains the weighing criteria (magnitude, probability, timeframe, reversibility, scope), how to compare in a speech, and a worked example.
Updated 2026-11-04
Why comparison decides close debates
In many debates, both sides make true points. A school phone ban may reduce distraction and also limit useful tools. If both are true, a judge has to decide which matters more. If neither side tells them, the judge decides alone, and may choose in a way neither expects.
Comparison, often called weighing or impact comparison, is the step that tells the judge how to decide. It is the difference between “we have a good argument” and “we win the debate”.
The weighing criteria
These are the standard ways to compare two arguments. Use whichever favors your side.
| Criterion | Question | Example |
|---|---|---|
| Magnitude | How big is the effect? | “Ours affects a million people; theirs affects a thousand.” |
| Probability | How likely is it to happen? | “Our benefit is certain once the policy passes; their harm depends on three other things going wrong.” |
| Timeframe | How soon does it happen, and how long does it last? | “Our harm is immediate; theirs is ten years away.” |
| Reversibility | Can it be undone? | “A mistake in our policy can be fixed next year; theirs cannot.” |
| Scope | How many people or places? | “Their benefit reaches one city; ours reaches the whole country.” |
| Directness | How closely does it link to the motion? | “Their impact depends on a chain of five steps; ours follows immediately.” |
| Severity | How serious is each person’s loss or gain? | “A loss of life outweighs a loss of convenience.” |
How to weigh in a speech
Use this four-step pattern for each comparison.
- Name the two impacts being compared.
- Grant the other side what is true: “Even if they are right that…”
- Choose a criterion and explain: “…ours is larger because…”
- State the result: “So the debate comes down to…, and we win it.”
A worked example
Motion: This house would make public transport free. Proposition impact: more people can afford to travel, cutting inequality in access to jobs. Opposition impact: lower fare revenue means fewer services.
A weak comparison: “Our impact is more important.” A strong one: “Even if fare revenue falls, as they say, the question is who bears the cost. Without a fare, a low-income worker who currently skips job interviews because of the ticket cost can attend them. That is a direct, immediate gain for people who are already worst off. Their harm is a possible fall in service frequency later, which depends on how the city chooses to fund services, and which the city can reverse. So on probability and reversibility, we win.”
The speaker grants the opposition’s point, picks two criteria, and gives a reason for each. That is weighing.
See comparison in a real debate
In long-form debates, the strongest closing statements weigh instead of repeating. Listen to the closing statements in the Doha Debates climate episode and note where speakers say what the audience should compare and why.
Watch: Climate Change | Full debate (Doha Debates). Watch how each side defines the problem before arguing about the solution.
Weighing values, not just facts
Some comparisons are about values: liberty against security, equality against efficiency. Here the criteria are not numbers. Explain why one value should take priority in this case. Useful questions: Which value is a precondition for the other? Which is more fundamental to the people affected? Which has the worse failure mode? If the audience shares a value, appeal to it. If not, explain why the value they hold supports your side.
Weighing when the other side weighs differently
Sometimes both teams weigh, but on different criteria. One side says magnitude, the other says probability. A judge cannot choose without help, so the next speaker has to compare the criteria themselves. Say why your criterion is the right one for this motion. A useful test is to ask what the decision-maker in the motion would care about. A government choosing a transport policy cares about reliability and cost over a decade, so a distant, speculative harm counts for less. A person choosing an irreversible medical procedure cares about reversibility, so even a small chance of permanent harm counts for more. Frame the choice of criterion as part of your argument, not an afterthought.
Then show that you win on your criterion and still do reasonably on theirs. That makes the decision easy for the judge.
Common weighing mistakes
Avoid these.
- Weighing only in the last speech.
- Comparing on a criterion that favors the other side.
- Saying “ours is more important” without a reason.
- Using too many criteria; choose one or two and develop them.
- Ignoring the other side’s weighing.
A one-sentence comparison you can use anywhere
When time is short, compress the weighing into a single sentence with the form: “Even if [their point], [our impact] is [larger / likelier / sooner / harder to reverse] because [reason].” For example: “Even if some families lose a little convenience, our benefit is larger, because it reaches every student and cannot be bought back later.” Practise writing three of these for any motion you prepare. They are short enough to deliver in ten seconds and specific enough for a judge to write down.
Comparing without being asked
Teams often wait for the final speech to weigh. A better habit is to weigh as you go. In your first speech, state which of your impacts is largest and why. In rebuttal, say why their best point is smaller. In the last speech, repeat the comparison in a sentence. By then the judge has heard it three times and will recall it.
Frequently asked questions
What is weighing in debate?
Weighing is comparing the importance of competing arguments so the judge can decide which side wins when both have valid points. It uses criteria such as magnitude, probability, timeframe and reversibility.
How do you compare two arguments?
Name both, concede what is true, choose a criterion that favors you, explain why, and state the result: “so we win this issue.”
What is the difference between rebuttal and weighing?
Rebuttal shows an argument is wrong, irrelevant or unproven. Weighing accepts that it may be true and shows that yours matters more.
What are the main weighing criteria?
Magnitude, probability, timeframe, reversibility, scope and directness. Some formats add severity.
When should I weigh in my speech?
Weigh in every speech after your first, and make the final comparison in your closing. Early weighing sets the terms of the debate.
Sources and further reading
- Debate competition events (National Speech & Debate Association)
- Parliamentary debate (Wikipedia)
- Argument and Persuasion (Stanford Encyclopedia of Philosophy)
- Argument (UNC Writing Center)
- Policy debate (Wikipedia)