Say what you expect — before you look
Sugar goes into water. You say: "It will dissolve in 20 seconds." Then you stir. Dissolve means the sugar mixes in and cannot be seen.
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Step 1 of 4
- A prediction: 20 seconds, before testing.
- Stir the sugar into the water.
- The real test finishes at 18 seconds.
- Said first, so the test could check it.
Prediction — what you expect, said before the test.
Said before the test, a prediction can be proved wrong. Said after, it proves nothing, because you already know the result.
A wrong prediction is useful. It is evidence: a fact that shows you something new. Changing your mind because of it is good science.