What Counts as Evidence?

Why It Matters

Imagine two friends are arguing about which route to school is faster. One says, “The Oak Street route is faster. I just know it.” The other says, “The Oak Street route is faster. I timed both routes three times, and Oak Street was faster every time by at least two minutes.” They’re making the same claim. But one of them has evidence and the other just has a feeling.

Evidence is what separates a strong argument from an empty one. It’s the part of an argument that you can point to, check, and show other people. Without evidence, a claim is just something someone said. With evidence, it’s something you can actually evaluate.

But here’s the part most people miss: not every fact is evidence for every claim. If you’re arguing that the soccer team needs new jerseys, the fact that you personally like the color blue is not evidence. But the fact that the current jerseys have holes and the numbers are peeling off — that’s evidence, because it connects to the claim that new jerseys are needed.

A Story

The Case of the Missing Garden

The neighborhood council was deciding whether to turn an empty lot on Birch Street into a community garden. Three neighbors came to the meeting with very different arguments.

Mrs. Tran said, “We need this garden. Community gardens increase property values. I read a study from the University of Pennsylvania that found property values within a quarter mile of new community gardens went up by about five percent.” She had printed out the study and brought it with her.

Mr. Kozlov said, “We definitely need this garden. My grandmother had a garden and it was the best thing about our neighborhood when I was a kid.” Everyone smiled. It was a nice memory. But Ms. Achebe, the council president, gently pointed out that a childhood memory, while meaningful, wasn’t evidence that this garden would benefit this neighborhood today.

Then Mr. Dunbar said, “I drove through the Millwood neighborhood last week and they had a community garden, and honestly it looked like a mess. Weeds everywhere. I don’t think gardens work.” Ms. Achebe asked a question: “Is one messy garden in a different neighborhood evidence that all community gardens fail?”

The council talked it through. Mrs. Tran had research — a study with data from many neighborhoods. That was strong evidence. Mr. Kozlov had a personal story — meaningful but not evidence about this situation. Mr. Dunbar had a single example from a different place — too little to draw a conclusion from.

They voted to try the garden, with a one-year review. Mrs. Tran’s evidence hadn’t guaranteed it would work, but it had given the council a real reason to believe it was worth trying. That’s what evidence does — it doesn’t remove all doubt, but it gives you something solid to stand on.

Vocabulary

Evidence

Information that helps show whether a claim is true or false. Evidence can be checked, shared, and examined by others.

Data

Facts or numbers collected by careful observation or research. Data is one of the strongest kinds of evidence because it can be measured and verified.

Anecdote

A personal story or single example. Anecdotes can be interesting, but one story doesn’t prove a general claim. You need more evidence than just one case.

Source

Where evidence comes from. Some sources are more reliable than others. A careful study is a stronger source than one person’s memory.

Verify

To check whether something is actually true. Good evidence can be verified — someone else could look it up, test it, or confirm it.

Guided Teaching

Evidence comes in different strengths. Think of it like a ladder. At the bottom, you have the weakest evidence: just someone’s feeling or guess. Higher up, you have a personal story or example. Higher still, you have multiple examples. And near the top, you have data — careful observations, measurements, or research that many people have checked.

Where on the evidence ladder would you put each person from the story? Mrs. Tran had a university study. Mr. Kozlov had a childhood memory. Mr. Dunbar had one example from another neighborhood. Which was strongest and why?

Here’s something important: even weak evidence isn’t worthless. Mr. Kozlov’s story about his grandmother’s garden doesn’t prove the Birch Street garden will work, but it does show that gardens can matter to neighborhoods. Mr. Dunbar’s example of the messy garden doesn’t prove all gardens fail, but it does raise a question about maintenance that the council should think about. Weak evidence can point you in a direction. It just can’t carry the whole argument.

Think about this: if Mr. Dunbar had visited ten community gardens and seven of them were messy and abandoned, would his evidence be stronger? Why?

The key test for evidence is: does this information actually make the claim more or less likely to be true? If someone claims the school library needs more books and their evidence is that the library smells funny, that’s information, but it’s not evidence for the claim about needing more books. If their evidence is that the library has fewer books per student than any other school in the district, that directly supports the claim.

Here’s a challenge: someone claims that homework helps students learn. What would count as evidence for this claim? What would count as evidence against it? How would you know if the evidence was strong or weak?

One more thing: evidence can be misleading. Someone might show you a true fact that seems to support their claim but actually doesn’t. “Our soccer team won ten games this season” sounds like evidence that the team is good. But what if they played twenty games and lost the other ten? The fact is true, but it doesn’t tell the whole story. Good thinkers don’t just ask “is there evidence?” — they ask “is this evidence complete and connected to the actual claim?”

When you get into the habit of asking for evidence, you’ll find that many claims people treat as obviously true have very little evidence behind them. And sometimes claims that sound strange turn out to have strong evidence. That’s why evidence matters more than feelings, more than confidence, and more than how many people believe something.

For Discussion

1. 1.What is evidence, and how is it different from just having an opinion?
2. 2.Why was Mrs. Tran’s evidence stronger than Mr. Kozlov’s story or Mr. Dunbar’s single example?
3. 3.Is a personal story ever useful in an argument? What can it do, and what can’t it do?
4. 4.What does it mean to “verify” evidence? Why is it important that evidence can be checked?
5. 5.Can you think of a time someone sounded very confident but didn’t actually have evidence for what they were saying?
6. 6.What’s the difference between evidence that’s connected to a claim and information that’s true but not relevant?
7. 7.Why did the council decide to try the garden with a one-year review? What does that tell you about how evidence works in real decisions?

Practice

Evidence Sorting

1. 1.Here is a claim: “Our school should start fifteen minutes later in the morning.”
2. 2.Below is a list of statements. Sort each one into three categories: Strong Evidence, Weak Evidence, or Not Evidence.
3. 3.1. “I hate waking up early.”
4. 4.2. “A study found that students who start school after 8:30 a.m. get better grades and are absent less often.”
5. 5.3. “My older sister’s school starts later and she likes it.”
6. 6.4. “The principal seems nice, so she’d probably agree.”
7. 7.5. “Our school nurse says she sees more kids in the morning complaining of tiredness and headaches than at any other time.”
8. 8.6. “Everybody wants to sleep in.”
9. 9.After sorting, discuss with a parent: why did you put each statement where you did? What makes evidence strong versus weak?
10. 10.Bonus: pick a claim you care about and gather the strongest evidence you can find. Can you find data, multiple examples, or an expert opinion that supports your claim?

Memory Questions

1. 1.What is evidence?
2. 2.What’s the difference between evidence and just having a confident opinion?
3. 3.What is an anecdote, and why isn’t a single anecdote enough to prove a general claim?
4. 4.In the story, whose evidence was strongest and why?
5. 5.What does it mean to verify evidence?
6. 6.Can a true fact be bad evidence for a particular claim? Give an example.