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Chapter 7 of 10All chapters

Chapter 7 of 10

Testing a claim

Hypotheses and p-values.

The logic

Assume nothing is going on, then ask how surprising the data would be under that assumption. A small p-value means the data would be unusual if nothing were happening.

  • It is not the probability that the hypothesis is true.
  • Significant does not mean large, important or replicable.

Effect size

With a large enough sample any trivial difference becomes significant. Always report how big the effect is alongside whether it passed a threshold.