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Lesson 9 of 17Test your idea1 min read

Choose one question to test

Write down the question before running the test.

The idea

A useful test starts with a specific question.

“Does this work?” could mean many things. Name what the program sees and what you will check afterward.

A small example

For our moving-average project:

When the latest price is above its three-price average, what happens to the next price?

This is a question about a price change. It is not yet a claim that a trade would make money.

Try it

Write four lines:

  • Input: the latest three prices.
  • Measurement: latest price minus their average.
  • Outcome: next price minus latest price.
  • Comparison: examine all eligible observations as a baseline.

Keep the meaning of “next” consistent with the way prices are sampled.

Check your work

The measurement uses the present and past. The outcome uses a later observation.

If you change the question after seeing the answer, record that change. It becomes a new test, not an invisible improvement to the old one.