Building a Case

Year 9 Power of Speech • Debate • Case Building

A case is the whole argument a team presents, not a pile of isolated points. It has a thesis, a few reasons that support it and evidence that makes those reasons credible. This page shows how to build a case that a team can deliver and an audience can follow.

Start with a thesis

The thesis is the one sentence the team wants the audience to accept. It should answer the motion directly and be arguable.

Motion	Weak thesis	Strong thesis
That homework should be optional.	“Homework is bad.”	“Homework should be optional because mandatory tasks punish students with unequal home conditions without improving learning.”
That social media does more harm than good.	“Social media is dangerous.”	“Social media does more harm than good because its business model rewards outrage and erodes face-to-face trust.”
That we should abolish school uniforms.	“Uniforms are boring.”	“Uniforms should be abolished because they impose a hidden cost on families without creating the belonging they promise.”
That Australia should ban single-use plastics.	“Plastic is bad.”	“Australia should ban single-use plastics because the environmental cost outweighs the convenience and viable alternatives exist.”

These are original teaching examples.

Three reasons are enough

A team needs a small number of developed reasons. Three is usually enough for a short debate. Each reason should be distinct: if two reasons say the same thing, combine them.

Reason type	Question it answers	Example
Harm	What problem exists now?	Mandatory homework widens inequality.
Cause	Why does the problem happen?	Home environments differ in space, quiet and support.
Solution	How does the motion fix it?	Optional homework lets students choose what they need.
Feasibility	Can it be done?	Schools already set optional extension tasks.
Principle	Is it fair or right?	Students should not be penalised for circumstances they cannot control.
Comparison	Is it better than the alternative?	The optional model preserves practice without the punishment.

The argument paragraph

Each reason can be built as a short paragraph: claim, explanation, evidence, analysis, link. The link returns to the thesis.

Move	Sentence
Claim	“Mandatory homework widens inequality.”
Explain	“Students with quiet space and adult help complete tasks faster than students without them.”
Evidence	“A 2023 survey of Australian secondary students found that ...” (use a real, checked source or label the example as illustrative).
Analyse	“This matters because the same task measures home advantage as much as learning.”
Link	“That is why homework should be optional rather than mandatory.”

Do not invent a statistic. If you do not have a source, use a reasoned example and say that it is an example.

The team split

A team split assigns each speaker a coherent part of the case. It should follow the argument, not the available time. Each speaker needs a job that can be explained in one sentence.

Speaker	Job	Content
First affirmative	Set the ground.	Definition, model, thesis, first reason.
Second affirmative	Build and defend.	Second and third reasons; rebuttal.
Third affirmative	Extend and compare.	Deeper analysis; respond to the negative case; summary.
First negative	Challenge the ground.	Accept or dispute the definition; negative thesis; first reason.
Second negative	Build and defend.	Second reason; rebuttal.
Third negative	Extend and compare.	Deeper analysis; respond to the affirmative; summary.

In a two-a-side format, the split is compressed: first speakers set the case and second speakers rebuild, rebut and summarise. The principle is the same.

Framing

Framing tells the audience how to weigh the debate. It identifies the central question and the criteria for judging it. A good frame is fair and broad enough to include both sides.

Frame	Central question	Criteria
Harm frame	Which option reduces more harm?	Scale, severity, likelihood.
Rights frame	Which option respects rights?	Dignity, autonomy, fairness.
Practicality frame	Which option works?	Cost, feasibility, unintended effects.
Principle frame	Which option is just?	Consistency, reciprocity, desert.
Comparative frame	Which option is better overall?	Benefits minus harms.

A frame should not stack the deck. “The only question is whether the policy is popular” is not a fair frame if popularity is irrelevant to the motion.

Signposting

Signposting makes the structure audible. Use simple signposts so the audience can follow without effort.

“Our case has three reasons.”
“My first reason is ...”
“That brings me to ...”
“Before I conclude, I want to answer ...”
“The central clash is ...”
“For those three reasons, we are proud to propose ...”

The one-page case outline

Section	Content
Motion	Exact words.
Definition	Key terms and scope.
Model	Agent, action, enforcement, exceptions.
Thesis	One sentence.
Frame	Central question and criteria.
Reason 1	Claim, evidence, analysis, link.
Reason 2	Claim, evidence, analysis, link.
Reason 3	Claim, evidence, analysis, link.
Split	Who says what.
Anticipated rebuttal	Two likely opposing points and answers.

One page, three reasons, one thesis. If the case cannot fit on a page, it is probably too complicated to deliver.

Activity: build a case in twenty minutes

Choose a motion.
Write the definition and model.
Draft a one-sentence thesis.
Choose three distinct reasons.
Add one piece of evidence or a labelled example to each.
Assign the reasons to speakers.
Pitch the case in one minute.

Common errors

No thesis. The audience cannot summarise the case.
Too many reasons. None is developed.
Repeating one reason. The case looks thin.
Evidence without analysis. The fact does not do the work.
Unbalanced split. One speaker carries everything.
No anticipated rebuttal. The team is surprised by obvious objections.

Next, study evidence and research to support the case. The rebuttal page teaches how to answer the other side.