How Definitions and Criteria Shape Arguments Before Evidence Arrives
Many arguments appear to disagree about evidence when the deeper disagreement is about what an important word means.
Is a policy fair? Is a student successful? Is a programme effective? Is a rule strict? Is an outcome better?
Before evidence can settle an argument, the reader often needs to know what standard the argument is using.
Quick Read
A definition tells us what a term includes and excludes. Criteria tell us what conditions must be met for an evaluation such as better, fair, successful or effective. If two sides use different definitions or criteria, they may appear to disagree even when each is reasoning consistently within a different frame.
Key term → definition → criteria → evidence → judgement.
One-Sentence Answer
Definitions and criteria shape an argument by deciding what counts before the evidence is even compared.
A Word Can Hide the Whole Argument
Consider:
This is the best school policy.
Best by which measure?
- lowest cost?
- highest academic outcomes?
- least disruption?
- greatest fairness?
- best long-term wellbeing?
Until the criterion is visible, the evaluation is incomplete.
The Developmental Route
| Stage | Definition and criteria control is becoming |
|---|---|
| Lower Primary | Explaining what a simple word means using examples |
| Middle Primary | Sorting examples and non-examples into categories |
| Upper Primary | Defining abstract words and identifying simple standards for judgement |
| Secondary | Testing contested definitions, competing criteria, category boundaries and value-laden terms in argument |
Definitions Draw Boundaries
A definition does more than explain a word. It decides which cases belong inside the category.
Suppose a writer defines volunteering as “unpaid work done to benefit others”.
Does helping a relative count? Does compulsory school service count? Does unpaid work for a company count?
Boundary cases reveal whether the definition needs refinement.
This connects to How Counterexamples Test Broad Claims and Reveal Their Limits.
Operational Definitions Make Abstract Ideas Testable
Some concepts are too broad to evaluate until the writer specifies how they will be measured.
If a school says a programme improved “engagement”, what counts as engagement?
- attendance?
- participation?
- voluntary reading?
- completion rates?
- self-reported interest?
Each operational definition may produce a different conclusion.
Evaluative Words Carry Criteria
Words such as better, fair, effective, responsible and successful cannot stand alone in serious argument.
They imply a standard.
To call something better is to compare it against a criterion, even when the criterion remains unstated.
Different Criteria Can Produce Different Winners
Imagine comparing two transport systems.
- System A is cheaper.
- System B is faster.
- System A serves more neighbourhoods.
- System B is more reliable during peak periods.
Which is better?
The answer depends on how cost, speed, coverage and reliability are weighted.
Evidence alone cannot rank them until the evaluation rule is stated.
Criteria Can Be Hidden Assumptions
The new method is better because it is faster.
The sentence assumes speed is a decisive criterion for quality.
If accuracy matters more, the conclusion may reverse.
Related article: How Hidden Assumptions Hold English Arguments Together.
Definitions Can Be Persuasive
Writers sometimes choose a definition that already favours their conclusion.
If a writer defines “responsible technology use” as “technology use that never distracts from study”, almost every recreational use may be excluded before the argument begins.
A reader should therefore ask whether the definition is neutral enough to test competing cases fairly.
Loaded Definitions Can Hide Judgement
Calling a protest “a disruption” foregrounds inconvenience. Calling it “public participation” foregrounds civic action.
The same event can be categorised through different concepts.
This connects definition to connotation and viewpoint.
Necessary and Sufficient Conditions Clarify Categories
A necessary condition must be present for something to qualify. A sufficient condition is enough by itself to establish the category.
Students do not always need the formal terminology, but the distinction is useful.
For example, being expensive may not be necessary or sufficient for something to count as luxurious. Price may matter, but quality, scarcity, design and experience may also shape the category.
Definitions Can Change During an Argument
A common reasoning problem occurs when a key word quietly changes meaning halfway through.
A writer may begin by using “freedom” to mean absence of legal restriction, then later use it to mean practical ability to act.
If the shift is not acknowledged, the argument can appear coherent while moving between different concepts.
Shared Words Do Not Guarantee Shared Definitions
Two sides may both support “fairness” while disagreeing about what fairness requires.
- equal treatment;
- equal opportunity;
- support according to need;
- reward according to contribution.
Without exposing the criteria, the debate can become circular.
Criteria Need Justification Too
Students sometimes define a standard and assume the job is finished.
But why should this criterion matter more than alternatives?
If a student evaluates schools only by examination results, the next question is whether that measure captures the purpose being discussed.
Evidence Must Match the Criterion
If the criterion is reliability, evidence about popularity may be irrelevant.
If the criterion is affordability, evidence about prestige may not answer the judgement.
Definition and criteria therefore control which evidence matters.
See How Students Judge Whether Evidence Is Relevant and Sufficient.
Definitions in Comprehension
When a writer uses an abstract word repeatedly, students should ask whether the text defines it directly, indirectly or through examples.
A passage may build its own specialised meaning for a familiar word.
Definitions in Argumentative Writing
Students improve essays when they identify contested terms early.
Instead of writing:
Social media is harmful.
They can specify what harm means in the argument: reduced sleep, anxiety, misinformation exposure, distraction or damage to relationships.
The definition makes the evidence burden clearer.
Related article: How Argumentative Writing Builds Claim, Evidence and Judgement.
A Worked Example
Question: Is homework effective?
Possible criteria:
- improved assessment performance;
- better retention;
- greater independence;
- efficient use of time;
- reasonable effect on wellbeing.
A study showing higher test scores may support one criterion but leave the others unanswered.
A strong judgement might therefore say that homework is effective for retention under certain conditions while still imposing costs if volume is excessive.
A Diagnostic Map
- Uses evaluative words without standards: ask “by what criterion?”
- Defines a term too broadly: test with boundary cases.
- Defines a term to guarantee the conclusion: compare competing definitions.
- Switches meaning mid-argument: track the key term consistently.
- Uses irrelevant evidence: match evidence to the stated criterion.
- Assumes criteria are self-evident: justify why they matter.
- Confuses definition with example: explain the general rule that includes the example.
- Argues over a label: expose the underlying conditions and evidence.
How We Teach Definitions and Criteria
We give students a contested word such as successful and ask them to create a definition that can classify real cases.
Other students then challenge it with examples near the boundary.
The class revises the definition until it becomes useful without becoming so broad that it says nothing.
Why a 3-Pax English Class Helps
Three students may rank the same option differently because each is using a different criterion. Making those criteria explicit turns disagreement into analysable structure.
The tutor can then ask whether the criteria should be combined, weighted or rejected.
What Parents Can Look For
When your child says something is “better”, “fair” or “effective”, ask:
What would have to be true for you to use that word?
Frequently Asked Questions
Can two definitions both be reasonable?
Yes. Many social and evaluative concepts have legitimate competing definitions. The writer should state the chosen definition and justify why it fits the question.
Does defining a word prove the argument?
No. A definition establishes the frame. Evidence is still needed to show that the case meets the criteria.
Why is this important in Secondary English?
Secondary argument increasingly uses abstract and evaluative concepts. Students need to recognise that important disagreements can begin at the level of definition and standards, before facts are compared.
The Larger Idea: The Measuring Stick Comes Before the Measurement
Evidence cannot tell us whether something is better until we know what counts as better.
Definitions establish the category. Criteria establish the measuring stick.
Strong arguments make the measuring stick visible before they announce the winner.
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