Understand evidence

Example

Use the same table-mounted arm and target: (20, 0, 15) cm from the base. Success means the tip ends within 1 cm of the target. These are fictional teaching cards, not actual run evidence.

• Card A · Request: “Move the tip to (20, 0, 15) cm.”

• Card B · Preview: “The target appears reachable.” A preview is a prediction before movement.

• Card C · Measured result: “After the attempt, the tip ended 2 cm from the target.” A measurement records what happened.

Your turn

Choose your answers before checking:

1. Which card tells you what actually happened: A, B or C?

2. Did the attempt meet the 1 cm success rule?

3. Suppose you have only A and B because no attempt was made. Which conclusion is justified: “It succeeded” or “It may be reachable, but it has not been tried”?

4. Suppose an attempt finished, but its final measurement is missing. Can you decide whether it met our success rule?

Check your reasoning

1. C. A describes the intention, B predicts feasibility, C supplies a measured outcome. A prediction can be wrong.

2. No. The measured 2 cm error exceeds our 1 cm tolerance, even though the preview looked promising. A finished attempt can still miss its target.

3. “It may be reachable, but it has not been tried.” A preview cannot establish successful movement.

4. No, the result is unknown from the supplied information. “Finished” tells us the attempt ended. Without its final measurement, we cannot check the distance. Missing evidence does not prove success or failure.

You can now separate what was requested, what was predicted and what was measured. Next, use measured results to plan a fair comparison.