See What Counts as Evidence

Let’s start with the one thing every solid claim is built from: evidence. Before you can weigh evidence or build a claim on it, you need to know exactly what counts as evidence in the first place, and what only looks like it. That is what this chapter is for.

Start with a Clear Definition of Evidence

We use the word “evidence” loosely in everyday talk, so it helps to pin it down. Evidence is information that changes how much you should believe a claim: it either raises or lowers how well that claim is supported. A weather app showing rain all week is evidence for the claim “the picnic will get rained out.” A friend saying “I just feel like it will be fine” is not, because it adds no information that makes the claim more or less supported.

Notice that evidence does not have to prove a claim outright. A single fact can nudge a claim a little more likely, or a little less likely, without settling it. Evidence is anything that moves the needle, not only the thing that ends the argument.

Tell Evidence Apart from How Sure You Feel

The most common beginner mistake is to treat strong feeling as if it were strong evidence. They are not the same thing, and keeping them apart is the whole game.

How sure you feel is about you: your confidence, your gut, your hope that a claim is true. Evidence is about the world: information that exists whether or not you feel anything at all. You can feel completely certain and have no evidence, and you can have solid evidence for something you find hard to believe.

This is why “how do you know?” is such a useful question. It quietly asks you to set your feeling aside and point to the information underneath. If you can point to something, you have evidence. If all you can point to is how sure you are, you have a feeling wearing the costume of a fact.

See Why Claims Built on Evidence Earn Trust

If feelings are easier to summon than evidence, why go to the trouble? Because evidence is the thing other people can check.

When you rest a claim on evidence, you hand others a way to test it for themselves. They can look at the same information and see whether it really supports what you say. A claim resting only on conviction offers nothing to check, so the only way to accept it is to trust the person, and that trust runs out fast. This is the quiet reason evidence-based claims travel further: they carry their own support with them, so they do not depend on how much anyone likes the person making them.

Watch This at Work in Two Everyday Decisions

Definitions land better once you see them in motion. Here are two ordinary decisions, side by side.

A claim built on evidence. Priya thinks her household is overspending on groceries. Instead of trusting the feeling, she looks at three months of receipts and sees the weekly total has climbed by about a third since spring. The receipts are evidence: they are information anyone could check, and they make the claim “we are spending more” clearly more supported. Her conclusion now stands on something outside her own worry.

A claim built on conviction. Her housemate Sam insists the rise is “obviously” because of the new grocery store down the road. It feels true to him, and he says it firmly. But he has no information connecting the store to the spending, only a hunch. Until he can point to something, a price comparison, or a change in where they shop, his claim is a feeling, not evidence, no matter how confident he sounds.

The difference is not who is louder, or even who turns out to be right. It is that Priya can show you why her claim holds, while Sam can only tell you that he believes it. That is what “counts as evidence” means in practice: something you can point to, that moves a claim, and that someone else could check for themselves.

Put those three tests together and you have a quick check you can run on any decision, not just these two. Take whatever you are leaning on and ask: Can I point to it, or is it only in my head? Does it actually move the claim, or does it just restate how I feel? Could someone else look at the same thing? Priya’s receipts pass all three, so they are evidence. Sam’s hunch fails all three, so it is not, however sure he sounds. The point is not that Priya is a careful person and Sam is a careless one, it is that the same simple test sorts their reasons for them, and it will sort yours too.

A hunch can absolutely point you toward the right answer, and it is a fine place to start looking. The catch is that being right by luck is not the same as knowing. Until you find the information that supports it, even a correct hunch is a claim you cannot yet defend, and you have no way to tell it apart from the hunches that are wrong.

Let’s Recap!

• Evidence is information that raises or lowers how well a claim is supported, not only what proves it outright;

• How strongly you feel about a claim is separate from how much evidence backs it, and confidence is never a substitute for support;

• Claims built on evidence earn trust because other people can check the information for themselves;

• A useful test for any piece of information is whether it makes the claim more or less likely to be true;

• If all you can point to is how sure you are, you have a feeling, not evidence.

Now that you can tell evidence from conviction, the next step is to recognize that evidence comes in several different forms. The next chapter walks you through the main kinds and what each one looks like.